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Structurally original oxathioethers macrocycles containing an exocyclic double-bond: synthesis, characterization, reactivity, and coordination
Tetrahedron 70 (2014) 5650e5658
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Tetrahedron journal homepage: www.elsevier.com/locate/tet
Structurally original oxathioethers macrocycles containing an exocyclic double-bond: synthesis, characterization, reactivity, and coordination Guillaume Carel a, Alina Saponar b, Nathalie Saffon c, Marc Vedrenne c, phane Massou d, Gabriela Nemes e, Ghassoub Rima a, David Madec a, *, Ste Annie Castel a, * Universit e de Toulouse, UPS, LHFA, CNRS UMR 5069, 118 Route de Narbonne, F-31062 Toulouse, France lniceanu, Nr: 1, RO-400084 Cluj-Napoca, Romania Institutul de Chimie, Raluca Ripan, Universitatea Babes¸-Bolyai, Str. M. Koga c Universit e de Toulouse, UPS, Institut de Chimie de Toulouse, ICT-FR2599, 118 Route de Narbonne, F-31062 Toulouse, France d LISBP/INSAT, UMR5504, UMR792, CNRS, INRA, INSA, 135 Avenue de Rangueil, 31077 Toulouse Cedex 04, France e , Universitatea Babes¸-Bolyai, Str. M. Koga lniceanu, Nr: 1, RO-400084 Cluj-Napoca, Romania Facultatea de Chimie s¸i Inginerie Chimica a
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a r t i c l e i n f o
a b s t r a c t
Article history: Received 6 March 2014 Received in revised form 5 June 2014 Accepted 18 June 2014 Available online 24 June 2014
New oxathioethers macrocycles have been synthesized and characterized. Each macrocycle consists in structurally defined ether and thioether moieties and an exocyclic double-bond (2aec) or a hydroxymethyl group (3aec). Macrocycles (2aec) have been synthesized by reaction of dianions of thioethers diols (1aec) with 3-chloro-2-chloromethylprop-1-ene. Their hydroboration/oxidation led to corresponding primary alcohols (3aec). Structures of compounds (2b) and (3a) have been determined by Xray diffraction. The reactivity of the hydroxyl group allowed the preparation of oxathioethers macrocycles bearing a polyether chain or a benzyl group (4a,b) and the synthesis of new bicyclic sandwich-type compounds (5a,b). The ability of these functionalized macrocycles to coordinate to palladium has been investigated. Ó 2014 Elsevier Ltd. All rights reserved.
Keywords: Oxathioethers Macrocycles Sandwich-type compounds Polyether chain NMR Coordination
1. Introduction The discovery of crown ethers1 was a major breakthrough in macromolecular chemistry, but the coordination abilities of these macrocyclic polyethers were essentially limited to alkali and alkaline earth metal cations, i.e., hard cations according to the HSAB model.2 In order to extend the scope of macrocyclic structures, analogous sulfur-bearing crown ethers have been synthesized. In particular, crown polythioethers (or thiacrowns) have been extensively studied and usually present high affinity for soft metal cations.3,4 Another step in crown macrocycles chemistry was achieved with the preparation of crown compounds containing different heteroatoms with new properties. Crown oxathioethers including both oxygen and sulfur atoms have thus been synthesized and
* Corresponding authors. Tel.: þ33 5 61556557; fax: þ33 5 61558204; e-mail address: [email protected] (D. Madec). URL: http://hfa.ups-tlse.fr/ http://dx.doi.org/10.1016/j.tet.2014.06.082 0040-4020/Ó 2014 Elsevier Ltd. All rights reserved.
studied.5,6 They present great interest in organometallic chemistry because of their ability to coordinate efficiently a wide range of cations.7 The characteristic exodentate coordination by sulfur atoms has notably been applied to the preparation of organometallic polymers.8,9 Thermodynamic data allowed to highlight the impact of the increasing number of sulfur atoms on the coordination properties. Indeed increasing number of sulfur atoms in a crown oxathioether improve its affinity for soft cation and reduce it for hard cations.10,11 Moreover reported complexes also emphasized the importance of structural features of the macrocycle, e.g., the relative positions of the two kinds of heteroatoms7a,12 or the number of carbon atoms between two heteroatoms.13,14 Although the coordination properties of a crown oxathioether cannot be easily predicted, that not prevent numerous applications: cation extraction6i,15 and transport,16 electrochemistry,17 spectrometry,18 photography,19 etc. The crown compounds including an exocyclic chemical function are of great interest due to their particular reactivity, which can, for example, be used to graft macrocycles on solid supports.15,20 The
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hydroxyl group is particularly useful because of its functionalization potential,21 and also because it increases the solubility of macrocycles in aqueous solution.22 Herein we describe the synthesis and characterization of a series of new oxathioethers macrocycles including an exocyclic double-bond, their conversion into corresponding primary alcohols via hydroboration/oxidation of the alkene function and the reactivity of the resulting hydroxyl group for the preparation of functionalized macrocycles. The ability of these new functionalized macrocycles to coordinate to palladium will be also investigated. 2. Results and discussion 2.1. Crown oxathioether syntheses Inspired by previous synthesis of alkene-substituted crown ethers23,24 we prepared crown oxathioethers 2aec by reaction of 3chloro-2-chloromethylprop-1-ene with the dianions of thioether diols 1aec including 2e4 thioether units (Scheme 1). While 3,6dithiaoctan-1,8-diol 1a was commercially available, compounds 1b and 1c were prepared from the corresponding dithiols in good yields (95%) using literature procedure.25
Scheme 1. Synthesis of crown oxathioethers 2aec.
Due to the relatively low solubility of diols 1b and 1c in ether solvents at rt, two different procedures were established. Compound 2a was prepared by concomitant addition of diol 1a and 3chloro-2-chloromethylprop-1-ene into a sodium hydride suspension in tetrahydrofuran. Compounds 2b and 2c were synthesized by heating diol 1b or 1c with elementary sodium in 1,4-dioxane before adding 3-chloro-2-chloromethylprop-1-ene. The reactions were carried out under high dilution conditions in refluxing solvent for 12e16 h. As often reported in two-component
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macrocyclisation,26 extensive formation of oligomeric and polymeric materials has been observed. Nevertheless, their formation can be minimized by the use of high dilution conditions and slow additions of reactants. Moreover, no template effects have been observed during the use of lithium or potassium bases. Column chromatography afforded pure products 2aec as yellow oils in 14e17% yield. The 1H and 13C NMR spectra of 2aec are almost identical in the crown ether region, with equivalent protons on a-positions to oxygen atoms. Chemical shifts of the allylic methylene (13C: 71.5e72.4 ppm and 1H: 4.06e4.10 ppm) in 2aec confirmed the ether bond formation. By contrast, signals of thioether groups strongly differ from 2a to 2b,c. While the CH2S protons appear as a singlet in 2a, complex sets of signals were observed in 2b,c (Fig. 1). A complete assignment of these signals was done by 2D experiments. High field 1H NMR analysis showed these shapes were characteristic of a second-order AA0 BB0 proton system attributed to H(f) (dA) and H(g) (dB). Modelization with WINDAISY software (BrukerÒ), allowed to determine the coupling constants of 2b and 2c, which are reported in the experimental part. All these spectroscopic data were consistent with literature information concerning crown and thiacrown ethers.24,27 In addition, highresolution mass spectrometry confirmed the formation of discrete crown oxathioethers 2aec. Slow evaporation of a solution of compound 2b in dichloromethane at rt gave crystals suitable for X-ray diffraction analysis. The asymmetric unit contains two independent but similar molecules, for clarity only one of them is shown in Fig. 2. The CeS (1.806e1.817 A), CeO (1.420e1.431 A), and CeC (1.500e1.512 A) bond lengths are consistent with average values related to ethers and thioethers compounds.28 The C1eC2 double bound has a normal length of 1.318 A.29 General conformation mostly follows the rules established by Wolf et al.25 for rationalizing the structure of crown oxathioethers: torsion angles of CeCeSeC chains from 48 to 73 are close to the gauche arrangement (60 ) and those of SeCeCeS chains of 166 are closed to anti angle (180 ). Subsequently, calculated distances between two sulfur atoms in thioether units ranged from 4.4 to 4.6 A thus matching previously published data.28 However, only half of CeO bounds present dihedral angles of 175e176 close to predicted anti angles, while the other ones present gauche-like torsion angles (72e73 ). Since these abnormal values concerned the bonds close to the
Fig. 1. Above: computational 1H NMR spectra for selected protons in compounds 2b and 2c (298 K). Below: experimental 1H NMR signals of selected protons in compounds 2aec.
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Fig. 2. Molecular structure of compound 2b in the solid state (ellipsoids set at 50% probability). For clarity, only one of the two independent molecules of the asymmetric unit is shown and hydrogen atoms are omitted. Selected bond distances [ A], bond angles [ ], and torsion angles [ ]: C1eC2 1.318(4), C2eC3 1.499(4), C4eC5 1.500(4), O1eC3 1.428(3), O1eC4 1.425(3), S1eC5 1.806(3), S1eC6 1.817(3), C1eC2eC3 121.9(3), C3eO1eC4 112.6(2), C5eS1eC6 105.2(2), C2eC3eO1eC4 72.7(3), C3eO1eC4eC5 176.3(2), O1eC4eC5eS1 68.4(3), C4eC5eS1eC6 72.6(2), C5eS1eC6eC7 47.5(2), S1eC6eC7eS2 166.1(2), C6eC7eS2eC8 55.3(2), C7eS2eC8eC9 58.4(2).
alkene function, the rigidity induced by the double bond from C1 to C12 must be responsible for these deviations from ideal conformation. Exocyclic double-bond can be directly grafted on a polysiloxane,20 but its main interest is to allow the access of various functional groups. Tomoi et al. showed that ketone and alcohol functions may be easily obtained from alkene crown ethers in moderate to good yields (60e90%).23 In order to facilitate further reactions on hydroxyl group, we decided to prepare the less hindered primary alcohols, thus hydroborationeoxidation procedure was chosen. This two-step reaction is very efficient for selective oxidation of double bonds,30 and has successfully been applied to the synthesis of hydroxyl crown ether.23 The preparation of organoborane was achieved by action of lithium borohydride in acidic conditions in tetrahydrofuran and followed by in situ oxidative workup (Scheme 2).
Scheme 2. Synthesis of crown oxathioethers 3aec.
Preliminary assays showed that stoichiometric conditions left a high proportion of starting materials 2aec so an excess of reactants was used at both steps to achieve full conversion. After column chromatography on silica gel, pure crowns oxathioethers were isolated as white solid (3a) or thick uncolored oils (3b,c) in 67%, 45%, and 37% yields, respectively. Besides the characteristic signals of the CH2OH group, a complex set of signals in the 1H NMR spectra should be noted, which consists in overlapped multiplet signals for non-equivalent hydrogen atoms of the methylene groups. Indeed, due to the presence of a pendant arm CH2OH, the intracyclic CH2O protons are non-equivalent generating second-order spin systems (Fig. 3): ABX system for H(c) protons with H(b), ABXY system appearing as pseudo-triplets for H(d) and H(e) protons. Slow recrystallization of 3a in chloroform gave suitable crystals for X-ray diffraction analysis. The asymmetric unit contains two molecules, for clarity only one of them is represented in Fig. 4.
Fig. 3. Experimental (solid line) and computational (dotted line) 1H NMR signals of selected protons of 3a.
Fig. 4. Molecular structure of compound 3a in the solid state (ellipsoids set at 50% probability). For clarity, only one of the two independent molecules of the asymmetric unit is shown and hydrogen atoms are omitted. Selected bond distances [ A], bond angles [ ], and torsion angles [ ]: C1eC2 1.519(6), C2eC3 1.586(8), C4eC5 1.516(9), O1eC1 1.425(6), O2eC3 1.414(9), O2eC4 1.443(8), S1eC5 1.804(7), S1eC6 1.818(8), C1eC2eC3 107.5(5), C3eO2eC4 113.8(5), C5eS1eC6 104.0(4), C2eC3eO2eC4 173.4(5), C3eO2eC4eC5 81.9(8), O2eC4eC5eS1 74.7(7), C4eC5eS1eC6 79.0(6), C5eS1eC6eC7 53.0(8), S1eC6eC7eS2 156.4(6).
As observed for 2b, the CeS (1.804e1.833 A), CeO (1.409e1.443 A), and CeC (1.488e1.586 A) bond lengths are consistent with comparable literature values.28 The C1eO1 bound length of 1.425 A lies within the expected range31 as well as the distance of 4.332 A between S1 and S2.28 This structure is moderately constrained with significant deviations from the ideal conformation:25 SeCeCeS and CeCeSeC torsion angles have the awaited order of magnitude with distortion from 7 to 19 from theoretical values, but some CeCeOeC torsion angles are strongly distorted, with variations up to 103 from the expected anti angle (180 ). In contrast with 2a where the observed distortions are clearly related to the presence of the double bond, 3a shows constraint mainly in the region between the oxygen and the sulfur atoms.
2.2. Hydroxy crown oxathioethers reactivity Applications could also require the crown macrocycle to have specific chemical or physical properties. The presence of a hydroxyl group offers the possibility to access to a lot of functionalized
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macrocycles by nucleophilic substitution reaction of a halide substrate. This is a very common route in the crown ether series,32e34 which has been rarely applied to crown oxathioethers.15 This prompted us to carry out some experiments on hydroxyl crown oxathioether 3a. Sodium hydride is known to be a Brønsted base compatible with cyclic ethers and thioethers.15 We used it to prepare the alkoxide salt from alcohol 3a in tetrahydrofuran at 50 C. The reaction with triethylene glycol 2-bromoethyl methylether or benzyl bromide leads to functionalized crown oxathioethers 4a and 4b, respectively (Scheme 3). After column chromatography pure compounds 4a and 4b were isolated as pale yellow oils (23 and 85% yields, respectively).
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2.3. Coordination properties The ability of these functionalized macrocycles to coordinate to a soft transition metal and more particularly to palladium was investigated. When using the same procedure used for the preparation of 6a38 namely reaction of stoichiometric amounts of 2a and PdCl2 in refluxing water/methanol solution, the corresponding complexes 6 were obtained in yields ranging from 36% to quantitative (Scheme 5). The coordination reactions using 2c and the bicyclic compounds 5a and 5b as ligands are more complex and led to a mixture of compounds that could not be identified.
Scheme 3. Synthesis of crown oxathioethers 4a,b. Scheme 5. Preparation of complexes 6.
The good yield obtained with benzyl chloride encouraged us to prepare new bicyclic sandwich-type molecules from the reaction of 1,2- or 1,3-dibromoxylene and 2 equiv of crown oxathioether 3a (Scheme 4) in the same experimental conditions. After column chromatography bicyclic compounds 5a and 5b were isolated as pale yellow oils in good yields (72%).
Fig. 5 shows the structure of 6b with selected bond lengths and angles. The main feature is the coordination of the palladium center to two S neighboring atoms from the macrocycle 2b with the two Cl atoms occupying the two other binding sites, the Pd(II) atom exhibiting a cis-type square planar geometry and the third sulfur and the two oxygen atoms remaining uncoordinated.
Scheme 4. Synthesis of bicyclic compounds 5a,b.
Comparison of 1H and 13C NMR spectra of 4a,b and 5a,b showed little difference in the crown oxathioether part of the molecule, so substitution by aryl group or polyether chain did not affect the structure of the macrocycle. The new functions were fully characterized in 1H and 13C NMR for 4a (polyether units) and for 4b and 5a,b (benzylic carbon and aryl group), showing chemical shifts consistent with comparable available experimental data.35 Alcohol conversion has been confirmed by the disappearance of OeH bound in infra-red spectra. The expected compounds were also characterized by high-resolution mass spectrometry. These new compounds present some interesting features compared to the hydroxyl crown oxathioether 3a. The long polyether chain grafted on 4a gives it a better affinity for polar solvents and makes it perfectly soluble in water medium whereas 3a was only slightly soluble in ethanol. Bicyclic compounds 5a,b bearing two crown ethers instead of oxathioethers are expected to present higher coordination properties than the mono-macrocycle derivatives, especially for the preparation of 1:2 ‘sandwich-like’ metaleligand complexes.36 This property can be applied for the extraction of cations in solutions.37
Fig. 5. Molecular structure of compound 6b in the solid state (ellipsoids set at 50% probability). The asymmetric unit contains two crystallographically independent molecules, only one of them is shown. For clarity, hydrogen atoms are omitted. Selected bond distances [ A] and bond angles [ ]: Pd(1)eS(1) 2.264(1), Pd(1)eS(2) 2.260(1), Pd(1)eCl(1) 2.320(1), Pd(1)eCl(2) 2.328(1); Cl(1)ePd(1)eCl(2) 95.07(3), Cl(1)ePd(1)eS(2) 174.50(3), Cl(1)ePd(1)eS(1) 86.66(3), Cl(2)ePd(1)eS(2) 89.65(3), Cl(2)ePd(1)eS(1) 178.11(3), S(2)ePd(1)eS(1) 88.59(3).
Concerning complexes 6c and 6d, two isomeric structures were identified by 1H NMR in 55:45 ratio. Slow evaporation of a solution of the mixture of these isomers for 6d in chloroform at rt gave monocrystals suitable for X-ray diffraction analysis and showing a co-crystallization of the two isomeric structures (Fig 6). Except the position of the hydrogen atom pointing up or down the cycle,
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two isomeric forms could be isolated with the hydroxy and benzyloxy substituted macrocyles. 4. Experimental section 4.1. General methods
Fig. 6. Molecular structures of compound 6d in the solid state (ellipsoids set at 50% probability). For clarity, the two isomeric structures are drawn separately (only atoms Pd1, S1, S2, Cl1, and Cl2 are not disordered). Hydrogen atoms are omitted. Selected bond distances [ A] and bond angles [ ]: Pd(1)eS(1) 2.258(1), Pd(1)eS(2) 2.273(2), Pd(1)eCl(1) 2.330(2), Pd(1)eCl(2) 2.315(2); Cl(1)ePd(1)eCl(2) 92.82(4), Cl(1)ePd(1)e S(2) 177.42(4), Cl(1)ePd(1)eS(1) 89.25(4), Cl(2)ePd(1)eS(2) 89.20(4), Cl(2)ePd(1)e S(1) 176.96(4), S(1)ePd(1)eS(2) 88.67(4).
the major difference lies in the deformation of the macrocycle with different torsion angles S(1)eCeCeS(2) of 47.78 and 60.72 indicating a strongly folded cycle for one isomer. As a result a large variation is observed between the O(1)eO(2) (2.951 A) and O(10 )e 0 O(2 ) (3.627 A) bond distances. The PdeS bond lengths (2.264(1), 2.260(1) A in 6b and 2.258(1), 2.273(2) A in 6d) are in the range of those previously observed in cis-Cl2S2-type Pd(II) complexes.7b,g,h,j,12 The 1H NMR spectra of complexes 6bed are almost identical in the aliphatic area except for the functional groups confirming the formation of similar 1:1 complexes. The greatest downfield shifts were observed for the methylene groups attached to sulfur atoms in agreement with the coordination of sulfur atoms to the palladium center. The coordination behavior of these macrocycles is similar in many respects to that of the two sulfur containing unsaturated ligand 2a. In each case, the exo-coordination was obtained with the formation of 1:1 complexes.
3. Conclusion New mixed functionalized oxathioethers macrocycles and new bicyclic sandwich-type derived compounds have been synthesized and characterized. These various macrocycles containing two ether bridges and 2e4 thioether bridges have been obtained by condensation reaction from dianions of thioethers diols with 3-chloro2-chloromethylprop-1-ene, then hydroboration/oxidation of the exocyclic double-bond. X-ray diffraction structures of macrocycle 2b functionalized by an exocyclic double-bond and macrocycle 3a substituted by a methyl hydroxyl group have been determined. The reactivity of the primary hydroxyl group upon halide compounds has been exploited through nucleophilic substitution, confirming the interest of these primary alcohols as customizable crown macrocycles. In this way properties like solvent solubility or spectroscopic properties can be adjusted to application requirement with no impact on the coordinating part of the molecule. Experiments involving affinity between these new macrocycles and palladium(II) have been investigated and afforded the corresponding exo-coordinated 1:1 complexes with the two S-donor atoms, and
All manipulations with air-sensitive materials were performed in a dry and oxygen-free atmosphere of argon by using standard schlenk-line. Solvents were purified with an MBRAUN SBS-800 purification system. NMR spectra were recorded in CDCl3 on a Bruker Avance II 300: 1H (300.18 MHz), 13C (75.48 MHz) at 298 K. Chemical shifts are expressed in parts per million (ppm) with residual solvent signals as internal standard. Mass spectrometry (MS) spectra were measured with a HewlettePackard 5989A in the electron impact mode (70 eV). High-resolution mass spectrometry (HRMS) spectra were measured with a GCT Premier Waters in DCI mode (CH4). IR spectra were measured on a Varian 640-IR FT-IR spectrometer. Melting points were measured with a sealed capillary using a Stuart automatic melting point SMP40 apparatus. Elemental analyses were realized by the central analysis service department of the Institut des Sciences Analytiques (ISA, UMR 5280) from Solaize or by the microanalysis service of the Laboratoire de Chimie de Coordination (LCC, UPR 8241) from Toulouse. Thin layer chromatographies (TLC) were performed over silica gel (Si60-F254, Merck). Column chromatographies were performed over silica gel (Si60 35e70 mm, SDS) and followed by TLC. 3,6Dithiaoctane-1,8-dithiol and 3-chloro-2-chloromethyl-1-propene were purchased from Acros. Thioether diols 1b,c were synthesized by following literature procedures.25 4.2. Syntheses of crown oxathioethers 4.2.1. 12-Methylene-1,10-dioxa-4,7-dithiacyclotridecane (2a).38 To a suspension of sodium hydride (90 mmol) in refluxing tetrahydrofuran (600 mL) were simultaneously added for 3e4 h 3,6-dithia1,8-octanediol (5.52 g, 30 mmol) and 3-chloro-2-chloromethyl-1propene (3.88 g, 31 mmol) solubilized in tetrahydrofuran (60 mL). After stirring for 16 h, the mixture was cooled, water (30 mL) was slowly added and the solvent was evaporated under reduced pressure. The aqueous layer was neutralized by hydrogen chloride solution (6 N), then extracted with dichloromethane (430 mL). Dichloromethane was evaporated under reduced pressure then the resulting solid was solubilized in dichloromethane/ethyl acetate (80:20) and filtered on silica gel. Solvent was removed from filtrate and the resulting orange solid was purified by column chromatography (dichloromethane/ethyl acetate, 95:5) to obtain product 2a as a yellow oil (Rf¼0.68, 14e17% yield). 1H NMR (CDCl3, 300 MHz): d 5.25 (t, 4J¼0.6 Hz, 2H, ]CH2), 4.06 (s, 4H, CH2eC]), 3.78 (t, 3J¼5.5 Hz, 4H, SeCH2eCH2eO), 2.95 (s, 4H, SeCH2eCH2eS), 2.77 (t, 3J¼5.5 Hz, 4H, SeCH2eCH2eO). 13C NMR (CDCl3, 300 MHz): d 143.0 (C]CH2), 117.8 (C]CH2), 72.5 (SeCH2eCH2eO), 72.4 (CH2eC]), 32.9 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3070, 2962, 2906, 1645, 1412, 1261, 1095, 1044, 865, 702. GCeMS (in CH2Cl2): m/z [M]þ¼234 (4%); [M(CH2CH2)]þ¼206 (3%), [M(CH2CH2O)þ1]þ¼191 (3%); [M(CH2CH2SCH2CH2)þ 1]þ¼147 (6%). HRMS (CI/CH4): [Mþ1] calcd for C10H19O2S2: 235.0826. Found: 235.0837. 4.2.2. 15-Methylene-1,13-dioxa-4,7,10-trithiacyclohexadecane (2b). A solution of 3,6,9-trithia-1,11-undecanediol (3.64 g, 15.0 mmol) and sodium (0.93 g, 40.0 mmol) in 1,4-dioxane (300 mL) was heated to reflux for 3 h to obtain the disodium salt as a pale brown solid. Then a solution of 3-chloro-2-chloromethyl-1-propene (1.88 g, 15.0 mmol) in 1,4-dioxane (150 mL) was added for 3 h in the refluxing suspension, then the mixture was stirred overnight. Water
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(15 mL) was slowly added at rt then the solvents were removed under reduced pressure. The residue was treated with water (15 mL) then extracted with dichloromethane (320 mL). After solvent evaporation, the resulting amber solid was vigorously extracted with diethyl ether (450 mL). The oil was purified by column chromatography (dichloromethane/ethyl acetate, 95:5) to obtain pure product as a yellow viscous oil (Rf¼0.74; 0.79 g, 17% yield). Crystals suitable for X-ray analysis were obtained by crystallization in dichloromethane. 1H NMR (CDCl3, 800 MHz): d 5.20 (quint, 4J¼0.4 Hz, 2H, ]CH2), 4.10 (t, 4J¼0.9 Hz, 4H, CH2eC]), 3.65 (t, 3 J¼6.0 Hz, 4H, SeCH2eCH2eO), 2.88 (AA0 BB0 syst., 2JAA0 ¼13.6 Hz, 3 JAB0 ¼3JA0 B¼11.0 Hz, 3JAB¼3JA0 B0 ¼5.2 Hz, 4H, SeCH2eCH2eS eCH2eCH2eO), 2.80 (AA0 BB0 syst., 2JBB0 ¼13.1 Hz, 3JAB0 ¼3JA0 B¼11.0 Hz, 3 JAB¼3JA0 B0 ¼5.2 Hz, 4H, SeCH2eCH2eSeCH2eCH2eO), 2.74 (t, 3 J¼6.0 Hz, 4H, SeCH2eCH2eO). 13C NMR (CDCl3, 75 MHz): d 143.0 (C]CH2), 116.0 (C]CH2), 71.5 (CH2eC]), 71.3 (SeCH2eCH2eO), 32.8 (SeCH2eCH2eS), 31.5 (SeCH2eCH2eO, SeCH2eCH2eS). IR (pure): n (cm1) 3074, 2914, 2851, 1655, 1423, 1265, 1199, 1098, 1044, 919, 718. MS (EI: 70 eV): m/z [M]þ¼294 (2%); [M(CH2CH2S)]þ¼233 (3%); [M((CH2CH2)2S)]þ¼206 (2%); [M((CH2CH2S)2)]þ¼174 (10%). HRMS (CI/CH4): [Mþ1] calcd for C12H23O2S3: 295.0860. Found: 295.0863. 4.2.3. 18-Methylene-1,16-dioxa-4,7,10,13-tetrathiacyclononadecane (2c). A solution of 3,6,9,12-tetrathia-1,14-tetradecanediol (1.51 g, 5.0 mmol) and sodium (0.31 g, 13.3 mmol) in 1,4-dioxane (100 mL) was heated at reflux for 2 h to obtain the disodium salt as a solid. A solution of 3-chloro-2-chloromethyl-1-propene (0.63 g, 5.0 mmol) in 1,4-dioxane (50 mL) was added at 80 C for 30 min then the mixture was heated at reflux and stirred overnight. 1,4-Dioxane was removed under reduced pressure and the resulting solid was extracted with dichloromethane (3100 mL). After solvent evaporation, the resulting brown solid was vigorously extracted by diethyl ether (325 mL). The oil was then purified by column chromatography (dichloromethane/ethyl acetate, 95:5) to obtain pure product as a yellow oil (Rf¼0.60; 0.29 g, 16% yield). 1H NMR (CDCl3, 300 MHz): d 5.23 (s, 2H, ]CH2), 4.08 (s, 4H, CH2eC]), 3.68 (t, 3J¼6.0 Hz, 4H, SeCH2eCH2eO), 2.89 (AA0 BB0 syst., 2JAA0 ¼13.6 Hz, 3 JAB0 ¼3JA0 B¼10.5 Hz, 3JAB¼3JA0 B0 ¼5.6 Hz, 4H, SeCH2eCH2eSeCH2e CH2eO), 2.84 (AA0 BB0 syst., 2JBB0 ¼13.6 Hz, 3JAB0 ¼3JA0 B¼10.5 Hz, 3 JAB¼3JA0 B0 ¼5.6 Hz, 4H, SeCH2eCH2eSeCH2eCH2eO), 2.82 (s, 4H, 3 SeCH2eCH2eSeCH2eCH2eS), 2.78 (t, J¼6.0 Hz, 4H, SeCH2eCH2eO). 13C NMR (CDCl3, 75 MHz): d 142.5 (C]CH2), 115.3 (C]CH2), 71.7 (CH2eC]), 71.2 (SeCH2eCH2eO), 33.3, 32.8 (SeCH2eCH2eSeCH2eCH2eO), 32.7 (SeCH2eCH2eSeCH2eCH2 eS), 32.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3073, 2914, 2851, 1655, 1423, 1266, 1200, 1098, 1043, 919, 719. MS (EI: 70 eV in CH2Cl2): m/z [M]þ¼354 (5%); [M(CH2CH2S)2]þ¼234 (3%); [M(CH2CH2S)2]þ¼174 (13%). HRMS (CI/CH4): [Mþ1] calcd for C14H27O2S4: 355.0894. Found: 355.0887. 4.3. General procedure for hydroborationeoxidation reactions (3aec) Lithium borohydride (4 M soln in THF, 0.35 mL, 1.4 mmol) then hydrogen chloride (2 M soln in diethyl ether, 1.0 mL, 2 mmol) were added to as solution of 2aec alkene macrocycle (1 mmol) in tetrahydrofuran (4 mL). The mixture was stirred for 1 h and water (0.4 mL) then sodium hydroxide solution (10 mol/L soln in water, 16 mmol) were slowly added. Hydrogen peroxide (30% w/w in water, 0.8 mL, 7 mmol) was added and the mixture was stirred for 1 h. The mixture was diluted by addition of THF (10 mL) and a sodium chloride solution (150 g/L, 10 mL) was added. The organic layer was separated by decantation, washed by saturated sodium chloride aqueous solution (5 mL), and dried on sodium sulfate. Solvents were removed in vacuo. Crude product was purified by
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column chromatography (dichloromethane/ethyl acetate, 1:1) to obtain the corresponding alcohol. 4.3.1. (1,10-Dioxa-4,7-dithiacyclotridecan-12-yl)methanol (3a). White solid gum (Rf¼0.40 [dichloromethane/ethyl acetate, 1:1], 67% yield). Crystals suitable for X-ray analysis were obtained by crystallization in chloroform. Mp¼50 C. 1H NMR (CDCl3, 300 MHz): d 3.83 (pseudo-t, J¼4.7 Hz, 4H, SeCH2eCH2eO), 3.76 (d, 3 J¼4.6 Hz, 2H, CH2eOH), 3.74 (dd, 2H, 2J¼9.3 Hz, 3J¼4.1 Hz, OeCHH0 eCH), 3.68 (dd, 2H, 2J¼9.3 Hz, 3J¼6.4 Hz, OeCHH0 eCH), 2.96 (s, 4H, SeCH2eCH2eS), 2.74 (pseudo-t, J¼4.7 Hz, 4H, SeCH2eCH2eO), 2.22 (br s, 1H, OH), 2.07e1.96 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d 74.2 (SeCH2eCH2eO), 69.5 (OeCH2eCH), 63.7 (CH2eOH), 41.8 (CH), 33.6 (SeCH2eCH2eS), 31.3 (SeCH2eCH2eO). IR (pure): n (cm1) 3430, 2911, 2860, 1479, 1405, 1368, 1276, 1115, 1031, 715. MS (EI: 70 eV): m/z [M]þ¼252 (10%); [MCH2CH2S]þ¼193 (25%); [M(CH2CH2S)2]þ¼133 (11%). Anal. Calcd for C10H20O3S2: C, 47.59; H, 7.99. Found: C, 47.22; H, 6.16%. 4.3.2. (1,13-Dioxa-4,7,10-trithiacyclohexadecan-15-yl)methanol (3b). Thick uncolored oil (Rf¼0.45 [dichloromethane/ethyl acetate, 1:1], 45% yield). 1H NMR (CDCl3, 300 MHz): d 3.74 (d, 3J¼5.1 Hz, 2H, CH2eOH), 3.67 (pseudo-t, 4H, 3J¼6.4 Hz, SeCH2eCH2eO), 3.72e3.60 (m, 4H, OeCH2eCH), 2.91e2.74 (m, 8H, SeCH2eCH2eS), 2.75 (t, 3J¼6.4 Hz, 4H, SeCH2eCH2eO), 2.46 (br s, 1H, OH), 2.10e2.03 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d 71.6 (SeCH2eCH2eO), 70.0 (OeCH2eCH), 63.6 (CH2eOH), 41.7 (CH), 32.7, 31.9 (SeCH2eCH2eS), 31.5 (SeCH2eCH2eO). IR (pure): n (cm1) 3440, 2916, 2865, 1462, 1423, 1364, 1261, 1094, 1032. MS (EI: 70 eV): m/z [M]þ¼312 (1%); [M(CH2CH2S)]þ¼253 (3%); [M(CH2CH2S)2]þ¼193 (3%). Anal. Calcd for C12H24O3S3: C, 46.12; H, 7.74. Found: C, 45.80; H, 7.84%. 4.3.3. (1,16-Dioxa-4,7,10,13-tetrathiacyclononadecan-18-yl)methanol (3c). Thick uncolored oil (Rf¼0.52 [dichloromethane/ethyl acetate, 1:1], 37% yield). 1H NMR (CDCl3, 300 MHz): d 3.78 (d, 3 J¼4.9 Hz, 2H, CH2eOH), 3.68 (t, 3J¼6.4 Hz, 4H, SeCH2eCH2eO), 3.72e3.60 (m, 4H, OeCH2eCH), 2.83 (br s, 12H, SeCH2eCH2eS), 2.76 (t, 3J¼6.4 Hz, 4H, SeCH2eCH2eO), 2.52 (s, 1H, OH), 2.14e2.07 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d 71.7 (SeCH2eCH2eO), 70.5 (OeCH2eCH), 63.9 (CH2eOH), 41.6 (CH), 33.1, 32.8, 32.7 (SeCH2eCH2eS), 32.0 (SeCH2eCH2eO). IR (pure): n (cm1) 3450, 2914, 2863, 1459, 1423, 1365, 1264, 1105, 1036, 715. MS (EI: 70 eV): m/z [M]þ¼372 (0.3%); [M(CH2CH2S)]¼313 (2%); [M(CH2CH2S)2]þ¼252 (3%); [M(CH2CH2S)3]þ¼193 (5%). Anal. Calcd for C14H28O3S4: C, 45.13; H, 7.57. Found: C, 45.72; H, 7.54%. 4.4. Reactivity of hydroxy crown oxathioethers 4.4.1. 12-(2,5,8,11,14-Pentaoxapentadecyl)-1,10-dioxa-4,7dithiacyclotridecane (4a). Sodium hydride (60% w/w in mineral oil, 40 mg, 1.0 mmol) washed by pentane (310 ml) was suspended at 0 C in tetrahydrofuran (3 mL), then alcohol 3a (127 mg, 0.5 mmol) in tetrahydrofuran (2 mL) was slowly added. The suspension was slowly warmed at rt and stirred for 1 h, then triethylene glycol, 2bromoethyl methyl ether (160 mL, 0.8 mmol) were added. After 1 h at rt the mixture was stirred at 50 C for 48 h. Water (2.5 mL) was slowly added then saturated sodium chloride solution (2.5 mL) was added and tetrahydrofuran phase was recovered by decantation. Aqueous phase was extracted by dichloromethane (35 mL) then organic phases were combined and dried on sodium sulfate. Solvents were removed under reduced pressure and crude product was purified by column chromatography (dichloromethane/ethyl acetate 1:1) to afford pure product as pale yellow oil (Rf¼0.14, 50 mg, 23% yield). 1H NMR (CDCl3, 300 MHz): 3.82e3.70 (m, 4H, SeCH2eCH2eO), 3.70e3.44 (m, 22H, CH2eOH, OeCH2eCH,
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[CH2CH2eO]4), 3.37 (s, 3H, OCH3), 2.94 (br s, 4H, SeCH2eCH2eS), 2.73e2.65 (m, 4H, SeCH2eCH2eO), 2.23e2.10 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): 74.2 (SeCH2eCH2eO), 71.9 (CH2eOH), 70.63, 70.60, 70.56, 70.54, 70.50, 70.4 ([CH2CH2eO]4), 69.3 (OeCH2eCH), 59.1 (OCH3), 40.4 (CH), 33.4 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 2908, 2866, 1455, 1405, 1290, 1259, 1353, 1107, 1036, 715. MS (EI: 70 eV): m/z [M]þ¼443 (1%); [M(CH2CH2OCH3)]þ¼383 (3%); [M(OCH2CH2)2OCH3]þ¼323 (1%). HRMS (CI/CH4): calcd for C19H39O7S2: 443.2137. Found: 443.2142. 4.4.2. 12-(Benzyloxymethyl)-1,10-dioxa-4,7-dithiacyclotridecane (4b). Sodium hydride (60% w/w in mineral oil, 40 mg, 1.0 mmol) washed by pentane (310 ml) was suspended at 0 C in tetrahydrofuran (3 mL), then alcohol 3a (130 mg, 0.5 mmol) in tetrahydrofuran (2 mL) was slowly added. The suspension was slowly warmed at rt and stirred for 1 h, and then benzyl bromide (90 mL, 0.8 mmol) was added. After 1 h at rt the mixture was stirred at 50 C until TLC (dichloromethane/ethyl acetate, 1:1) had showed full disappearance of reactant 3a. Water (2.5 mL) was slowly added then saturated sodium chloride aqueous solution (2.5 mL) was added and tetrahydrofuran phase was recovered by decantation. Aqueous phase was extracted by dichloromethane (35 mL) then organic phases were combined and dried on sodium sulfate. Solvents were removed under reduced pressure to afford pure product as pale yellow oil (146 mg, 85% yield). 1H NMR (CDCl3, 300 MHz): 7.45e7.25 (m, 5H, C6H5), 4.53 (s, 2H, CH2Ph), 3.87e3.71 (m, 4H, SeCH2eCH2eO), 3.67 (dd, 2J¼9.0 Hz, 3J¼3.6 Hz, 2H, OeCHH0 eCH), 3.55 (dd, 2J¼9.0 Hz, 3J¼7.1 Hz, 2H, OeCHH0 eCH), 3.50 (d, 2J¼6.7 Hz, 2H, CHeCH2eOBn), 3.03e2.93 (m, 4H, SeCH2eCH2eS), 2.76e2.69 (m, 4H, SeCH2eCH2eO), 2.28e2.20 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): 138.4 (Cipso), 128.5 (Cm), 127.7 (Cp), 127.6 (Co), 74.3 (SeCH2eCH2eO), 73.2 (CH2Ph), 69.43, 69.38 (CHeCH2eOBn, OeCH2eCH), 40.6 (CH), 33.5 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3300e3000, 2912, 2856, 1453, 1404, 1366, 1263, 1204, 1094, 850, 698. MS (EI: 70 eV): m/z [M]þ¼342 (1%); [M(CH2CH2S)]þ¼283 (1%); [M(CH2CH2S) OBn]þ¼176 (3%). HRMS (CI/CH4): [Mþ1] calcd for C17H27O3S2: 343.1402. Found: 343.1400. 4.5. General procedure for synthesis of bicyclic compounds (5a,b) Sodium hydride (60% w/w in mineral oil, 46 mg, 1.2 mmol) washed by pentane (310 ml) was suspended at 0 C in tetrahydrofuran (2 mL), then alcohol 3a (128 mg, 0.5 mmol) in tetrahydrofuran (2 mL) was slowly added. The suspension was slowly warmed at rt and stirred for 1 h, then 1,2- and 1,3bis(bromomethyl)benzene (66 mg, 0.25 mmol) in tetrahydrofuran (1 mL) was added. The mixture was stirred at 50 C until TLC (dichloromethane/ethyl acetate, 1:1) had showed full disappearance of reactant 3a (16 h). Water (2.5 mL) then saturated sodium chloride aqueous solution (2.5 mL) was added and tetrahydrofuran phase was recovered by decantation. Aqueous phase was extracted by dichloromethane (35 mL) then organic phases were combined and dried on sodium sulfate. Solvents were removed and the orange solid was purified by column chromatography (dichloromethane/ethanol 96:4) to afford pure product 5a or 5b as yellow oil. 4.5.1. 1,2-Bis[((1,10-dioxa-4,7-dithiacyclotridecan-12-yl)methoxy) methyl]benzene (5a). Yellow oil (Rf¼0.48 [dichloromethane/ethanol 96:4], 110 mg, 72% yield). 1H NMR (CDCl3, 300 MHz): 7.40e7.38 (m, 2H, CoH), 7.33e7.30 (m, 2H, CmH), 4.57 (s, 4H, CH2Ar), 3.85e3.72 (m, 8H, SeCH2eCH2eO), 3.66 (dd, 2J¼9.0 Hz, 3J¼3.6 Hz, 4H, OeCHH0 eCH), 3.54 (dd, 2J¼9.0 Hz, 3J¼7.1 Hz, 4H, OeCHH0 eCH),
3.50 (d, 2J¼6.7 Hz, 4H, CHeCH2eO), 2.97 (s, 8H, SeCH2eCH2eS), 2.74e2.71 (m, 8H, SeCH2eCH2eO), 2.30e2.15 (m, 2H, CH). 13C NMR (CDCl3, 75 MHz): 136.4 (Cipso), 128.7 (Co), 127.9 (Cm), 74.3 (SeCH2eCH2eO), 70.9 (CH2Ar), 69.6 (CHeCH2eO), 69.4 (OeCH2eCH), 40.6 (CH), 33.5 (SeCH2eCH2eS), 31.3 (SeCH2eCH2eO). IR (pure): n (cm1) 3040, 2913, 2859, 1455, 1404, 1367, 1268, 1205, 1116, 1189, 1044. MS (EI: 70 eV): m/z [M]þ¼606 (1%); [M(CH2CH2S)2]þ¼487 (0.5%); [M(3a)]þ¼354 (6%). HRMS (CI/CH4): [Mþ1] calcd for C28H47O6S4: 607.2256. Found: 607.2280. 4.5.2. 1,3-Bis[((1,10-dioxa-4,7-dithiacyclotridecan-12-yl)methoxy) methyl]benzene (5b). Yellow oil (Rf¼0.60 [dichloromethane/ethanol 96:4], 109 mg, 72% yield). 1H NMR (CDCl3, 300 MHz): 7.40e7.27 (m, 4H, C6H4), 4.53 (s, 4H, CH2Ar), 3.84e3.73 (m, 8H, SeCH2eCH2eO), 3.67 (dd, 2J¼9.0 Hz, 3J¼3.6 Hz, 4H, OeCHH0 eCH), 3.55 (dd, 2J¼9.0 Hz, 3J¼7.1 Hz, 4H, OeCHH0 eCH), 3.51 (d, 2J¼6.7 Hz, 4H, CHeCH2eO), 2.98 (s, 8H, SeCH2eCH2eS), 2.75e2.71 (m, 8H, SeCH2eCH2eO), 2.28e2.20 (m, 2H, CH). 13C NMR (CDCl3, 75 MHz): 138.5 (Cipso), 128.6 (Cm), 126.9, 126.7 (Co), 74.2 (SeCH2eCH2eO), 73.1 (CH2Ar), 69.5 (CHeCH2eO), 69.3 (OeCH2eCH), 40.6 (CH), 33.4 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3026, 2913, 2857, 1457, 1404, 1366, 1274, 1204, 1100e1092, 1041. MS (EI: 70 eV): m/z [M(CH2CH2S)2]þ¼487 (1%); [M(3a)]þ¼354 (15%). HRMS (CI/CH4): [Mþ1] calcd for C28H47O6S4: 607.2256. Found: 607.2269. 4.6. Synthesis of palladium complexes 4.6.1. Complex[Pd(2b)Cl2] (6b). Macrocycle 2b (56 mg, 0.2 mmol) was added to a suspension of palladium(II) dichloride (36 mg, 0.2 mmol) in a 1:1 methanol/water mixture (30 mL) and heated to reflux for 2 h. The orange solution was then filtered and the removal of solvents afforded compound 6b as an orange gum (quantitative yield). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a chloroform solution. 1H NMR (CDCl3, 300 MHz): d 5.28 and 5.23 (s, 21H, ]CH2), 4.70e2.60 (m, 20H, CH2). 13C NMR (CDCl3, 75 MHz): d 141.6 (C]CH2), 117.7 (C]CH2), 73.0 and 72.4 (SeCH2eCH2eO), 72.10 and 72.07 (CH2eC]), 38.9, 37.9, 37.4, 37.3 (SeCH2eCH2eS), 32.1, 31.2 (SeCH2eCH2eO, SeCH2eCH2eS). IR (pure): n (cm1) 2919, 2854, 1647, 1412, 1290, 1094, 1046, 849. MS FAB-(noba): m/z [MCl]þ¼437 (100%); [M2Cl]þ¼400 (26%). calcd for C12Cl2H22O2PdS3: C, 30.55; H, 4.70. Found: C, 30.35; H, 4.25. 4.6.2. Complex[Pd(3a)Cl2] (6c). Macrocycle 3a (50 mg, 0.2 mmol) was added to a suspension of palladium dichloride (38 mg, 0.2 mmol) in a 1:1 methanol/water mixture (30 mL) and refluxed for 2 h. After cooling to rt and evaporation of the solvents, the green residue was extracted with ethanol (40 mL then 25 mL). After filtration and evaporation of the ethanol in vacuo, compound 6c was isolated as yellow crystalline product (70 mg, 81% yield). Mp: 87 C. 1 H NMR (CD3CN, 300 MHz): d (Isomer 1, 55%): 4.47 (ddd, 2J¼11.3 Hz, 3 J¼8.9 Hz, 3J¼2.3 Hz, 2H, SeCH2CHH0 eO), 3.83 (ddd, 2J¼11.3 Hz, 3 J¼5.1 Hz, 3J¼2.5 Hz, 2H, SeCH2CHH0 eO), 3.85e3.60 (m, 2H, SeCHH0 eCHH0 eS), 3.75 (d, 3J¼4.6 Hz, 4H, OeCH2eCH) 3.53 (d, 3 J¼6.2 Hz, 2H, CH2OH), 3.42 (ddd, 2J¼14.9 Hz, 3J¼8.9 Hz, 3J¼2.5 Hz, 2H, SeCHH0 CH2eO), 3.07e2.90 (m, 2H, SeCHH0 eCHH0 eS), 2.90e2.73 (m, 2H, SeCHH0 CH2eO). d (Isomer 2, 45%): 4.39 (ddd, 2 J¼11.3 Hz, 3J¼8.7 Hz, 3J¼2.3 Hz, 2H, SeCH2CHH0 eO), 3.92 (ddd, 2 J¼11.3 Hz, 3J¼5.1 Hz, 3J¼3.0 Hz, 2H, SeCH2CHH0 eO), 3.85e3.75 (m, 2H, OeCHH0 eCH), 3.85e3.60 (m, 2H, SeCHH0 eCHH0 eS), 3.70e3.50 (m, 2H, OeCHH0 eCH), 3.48 (d, 3J¼6.2 Hz, 2H, CH2OH), 3.38 (ddd, 2 J¼14.9 Hz, 3J¼8.7 Hz, 3J¼2.4 Hz, 2H, SeCHH0 CH2eO), 3.07e2.90 (m, 2H, SeCHH0 eCHH0 eS), 2.90e2.73 (m, 2H, SeCHH0 CH2eO). Due to overlap with solvent peak at 2.2 ppm, the chemical shift of methane proton has not been determined. 13C NMR (CD3CN, 75 MHz): d (Isomer 1): 73.5 (OeCH2eCH), 70.8 (SeCH2CH2eO), 61.5
G. Carel et al. / Tetrahedron 70 (2014) 5650e5658
(CH2OH), 41.2 (CH), 39.8 (SeCH2CH2eS), 37.9 (SeCH2CH2eO). d (Isomer 2): 73.9 (OeCH2eCH), 71.1 (SeCH2CH2eO), 61.8 (CH2OH), 43.7 (CH), 40.1 (SeCH2CH2eS), 37.8 (SeCH2CH2eO). IR (KBr): n (cm1) 3480, 2923, 2854, 1465, 1261, 1126, 1097, 1029. MS FAB(noba): m/z 395 (73%) [MCl]þ, 358 (100%) [M2Cl]þ. 4.6.3. Complex[Pd(4b)Cl2] (6d). Macrocycle 4b (70 mg, 0.2 mmol) was added to a suspension of palladium dichloride (36 mg, 0.2 mmol) in a 1:1 methanol/water mixture (30 mL) and refluxed for 2 h. After evaporation of the solvents, the resulting orange solid was extracted with ethanol (50 then 220 mL) at 60 C. After filtration, ethanol was removed under vacuum. The residue was washed with diethyl ether (25 mL) and compound 6d was obtained as an orange powder (38 mg, 36% yield). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a chloroform solution. Mp: 72 C. 1H NMR (CDCl3, 300 MHz): d (Isomer 1, 55%): 7.44e7.30 (m, 5H, C6H5), 4.70e4.64 (m, 2H, SeCH2CHH0 eO), 4.54 (s, 2H, CH2Ph), 4.00e3.50 (m, 10H, OeCH2eCH, SeCH2CHH0 eO, SeCHH0 CH2eO, SeCHH0 eCHH0 eS), 3.51 (d, 2J¼6.9 Hz, 2H, CHeCH2OBn), 2.95e2.82 (m, 2H, SeCHH0 eCHH0 eS), 2.82e2.72 (m, 2H, SeCHH0 CH2eO), 2.40e2.20 (m, 1H, CH). d (Isomer 2, 45%): 7.44e7.30 (m, 5H, C6H5), 4.70e4.64 (m, 2H, SeCH2CHH0 eO), 4.51 (s, 2H, CH2Ph), 4.00e3.50 (m, 10H, OeCH2eCH, SeCH2CHH0 eO, SeCHH0 CH2eO, SeCHH0 eCHH0 eS), 3.40 (d, 2J¼6.0 Hz, 2H, CHeCH2OBn), 3.10e2.95 (m, 2H, SeCHH0 eCHH0 eS), 2.82e2.72 (m, 2H, SeCHH0 CH2eO), 2.30e2.20 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d (Isomer 1) 138.0 (Cipso), 128.5 (Cm), 128.0, 127.8 (Co, Cp), 73.9 (OeCH2eCH), 73.2 (CH2Ph), 71.8 (SeCH2CH2eO), 68.4 (CHeCH2OBn), 39.7 (SeCH2CH2eS), 38.5 (CH), 38.0 (SeCH2CH2eO). d (Isomer 2): 138.4 (Cipso), 128.6 (Cm), 127.94, 127.90 (Co, Cp), 75.3 (OeCH2eCH), 73.5 (CH2Ph), 72.1 (SeCH2CH2eO), 69.4 (CHeCH2OBn), 41.5 (CH), 40.1 (SeCH2CH2eS), 38.2 (SeCH2CH2eO). IR (KBr): 3019, 2926, 2857, 1452, 1419, 1389, 1255, 1206, 1152, 1117, 849. MS FAB-(noba): m/z 485 (100%) [MCl]þ, 448 (66%) [M2Cl]þ. Anal. Calcd for C17H26Cl2O3PdS2: C, 39.28; H, 5.04. Found: C, 38.40; H, 4.61.
Supplementary data NMR spectroscopic data including 1H and 13C NMR spectra for compounds 2aec, 3aec, 4a,b, 5a,b and 6bed, and crystallographic data for 2b, 3a, 6b and 6d. This material is available free of charge via the internet. Supplementary data associated with this article can be found in the online version, at http://dx.doi.org/10.1016/ j.tet.2014.06.082.
References and notes 1. 2. 3. 4. 5.
6.
7.
4.7. X-ray crystallography The data of the structures for compounds 2b, 3a, 6b, and 6d were collected on a Bruker-AXS kappa APEX II Quazar diffractometer using a 30 W aircooled microfocus source (ImS) with focusing multilayer optics at a temperature of 193(2)K, with graphitemonochromated MoKa radiation (wavelength¼0.71073 A) by using 4- and u-scans. The data were integrated with SAINT,39 and an empirical absorption correction with SADABS40 was applied. The structures were solved by direct methods, using SHELXS-97 and refined using the least-squares method on F2.41 All non-H atoms were treated anisotropically. All H atoms attached to C atoms were fixed geometrically and treated as riding on their parent atoms. H atoms of OeH groups (3a) were located in difference Fourier maps and included in the subsequent refinement without using restraints. CCDC 969058 (2b), CCDC 969059 (3a), CCDC 1006504 (6b), and CCDC 908222 (6d), contain the supplementary crystallographic data. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif (or from the CCDC, 12 Union Road, Cambridge CB2 1EZ, UK; fax: þ44 1223 336 033; or [email protected]). Acknowledgements This work was supported by the Centre National de la Recherche de Toulouse and the Agence Scientifique (CNRS), the Universite Nationale pour la Recherche (ANR-08-CSOG-00). G.C. is grateful to the ANR for his Ph.D. grant and G.N. for 129/2008 PCCE grant.
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10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
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Structurally original oxathioethers macrocycles containing an exocyclic double-bond: synthesis, characterization, reactivity, and coordination Guillaume Carel a, Alina Saponar b, Nathalie Saffon c, Marc Vedrenne c, phane Massou d, Gabriela Nemes e, Ghassoub Rima a, David Madec a, *, Ste Annie Castel a, * Universit e de Toulouse, UPS, LHFA, CNRS UMR 5069, 118 Route de Narbonne, F-31062 Toulouse, France lniceanu, Nr: 1, RO-400084 Cluj-Napoca, Romania Institutul de Chimie, Raluca Ripan, Universitatea Babes¸-Bolyai, Str. M. Koga c Universit e de Toulouse, UPS, Institut de Chimie de Toulouse, ICT-FR2599, 118 Route de Narbonne, F-31062 Toulouse, France d LISBP/INSAT, UMR5504, UMR792, CNRS, INRA, INSA, 135 Avenue de Rangueil, 31077 Toulouse Cedex 04, France e , Universitatea Babes¸-Bolyai, Str. M. Koga lniceanu, Nr: 1, RO-400084 Cluj-Napoca, Romania Facultatea de Chimie s¸i Inginerie Chimica a
b
a r t i c l e i n f o
a b s t r a c t
Article history: Received 6 March 2014 Received in revised form 5 June 2014 Accepted 18 June 2014 Available online 24 June 2014
New oxathioethers macrocycles have been synthesized and characterized. Each macrocycle consists in structurally defined ether and thioether moieties and an exocyclic double-bond (2aec) or a hydroxymethyl group (3aec). Macrocycles (2aec) have been synthesized by reaction of dianions of thioethers diols (1aec) with 3-chloro-2-chloromethylprop-1-ene. Their hydroboration/oxidation led to corresponding primary alcohols (3aec). Structures of compounds (2b) and (3a) have been determined by Xray diffraction. The reactivity of the hydroxyl group allowed the preparation of oxathioethers macrocycles bearing a polyether chain or a benzyl group (4a,b) and the synthesis of new bicyclic sandwich-type compounds (5a,b). The ability of these functionalized macrocycles to coordinate to palladium has been investigated. Ó 2014 Elsevier Ltd. All rights reserved.
Keywords: Oxathioethers Macrocycles Sandwich-type compounds Polyether chain NMR Coordination
1. Introduction The discovery of crown ethers1 was a major breakthrough in macromolecular chemistry, but the coordination abilities of these macrocyclic polyethers were essentially limited to alkali and alkaline earth metal cations, i.e., hard cations according to the HSAB model.2 In order to extend the scope of macrocyclic structures, analogous sulfur-bearing crown ethers have been synthesized. In particular, crown polythioethers (or thiacrowns) have been extensively studied and usually present high affinity for soft metal cations.3,4 Another step in crown macrocycles chemistry was achieved with the preparation of crown compounds containing different heteroatoms with new properties. Crown oxathioethers including both oxygen and sulfur atoms have thus been synthesized and
* Corresponding authors. Tel.: þ33 5 61556557; fax: þ33 5 61558204; e-mail address: [email protected] (D. Madec). URL: http://hfa.ups-tlse.fr/ http://dx.doi.org/10.1016/j.tet.2014.06.082 0040-4020/Ó 2014 Elsevier Ltd. All rights reserved.
studied.5,6 They present great interest in organometallic chemistry because of their ability to coordinate efficiently a wide range of cations.7 The characteristic exodentate coordination by sulfur atoms has notably been applied to the preparation of organometallic polymers.8,9 Thermodynamic data allowed to highlight the impact of the increasing number of sulfur atoms on the coordination properties. Indeed increasing number of sulfur atoms in a crown oxathioether improve its affinity for soft cation and reduce it for hard cations.10,11 Moreover reported complexes also emphasized the importance of structural features of the macrocycle, e.g., the relative positions of the two kinds of heteroatoms7a,12 or the number of carbon atoms between two heteroatoms.13,14 Although the coordination properties of a crown oxathioether cannot be easily predicted, that not prevent numerous applications: cation extraction6i,15 and transport,16 electrochemistry,17 spectrometry,18 photography,19 etc. The crown compounds including an exocyclic chemical function are of great interest due to their particular reactivity, which can, for example, be used to graft macrocycles on solid supports.15,20 The
G. Carel et al. / Tetrahedron 70 (2014) 5650e5658
hydroxyl group is particularly useful because of its functionalization potential,21 and also because it increases the solubility of macrocycles in aqueous solution.22 Herein we describe the synthesis and characterization of a series of new oxathioethers macrocycles including an exocyclic double-bond, their conversion into corresponding primary alcohols via hydroboration/oxidation of the alkene function and the reactivity of the resulting hydroxyl group for the preparation of functionalized macrocycles. The ability of these new functionalized macrocycles to coordinate to palladium will be also investigated. 2. Results and discussion 2.1. Crown oxathioether syntheses Inspired by previous synthesis of alkene-substituted crown ethers23,24 we prepared crown oxathioethers 2aec by reaction of 3chloro-2-chloromethylprop-1-ene with the dianions of thioether diols 1aec including 2e4 thioether units (Scheme 1). While 3,6dithiaoctan-1,8-diol 1a was commercially available, compounds 1b and 1c were prepared from the corresponding dithiols in good yields (95%) using literature procedure.25
Scheme 1. Synthesis of crown oxathioethers 2aec.
Due to the relatively low solubility of diols 1b and 1c in ether solvents at rt, two different procedures were established. Compound 2a was prepared by concomitant addition of diol 1a and 3chloro-2-chloromethylprop-1-ene into a sodium hydride suspension in tetrahydrofuran. Compounds 2b and 2c were synthesized by heating diol 1b or 1c with elementary sodium in 1,4-dioxane before adding 3-chloro-2-chloromethylprop-1-ene. The reactions were carried out under high dilution conditions in refluxing solvent for 12e16 h. As often reported in two-component
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macrocyclisation,26 extensive formation of oligomeric and polymeric materials has been observed. Nevertheless, their formation can be minimized by the use of high dilution conditions and slow additions of reactants. Moreover, no template effects have been observed during the use of lithium or potassium bases. Column chromatography afforded pure products 2aec as yellow oils in 14e17% yield. The 1H and 13C NMR spectra of 2aec are almost identical in the crown ether region, with equivalent protons on a-positions to oxygen atoms. Chemical shifts of the allylic methylene (13C: 71.5e72.4 ppm and 1H: 4.06e4.10 ppm) in 2aec confirmed the ether bond formation. By contrast, signals of thioether groups strongly differ from 2a to 2b,c. While the CH2S protons appear as a singlet in 2a, complex sets of signals were observed in 2b,c (Fig. 1). A complete assignment of these signals was done by 2D experiments. High field 1H NMR analysis showed these shapes were characteristic of a second-order AA0 BB0 proton system attributed to H(f) (dA) and H(g) (dB). Modelization with WINDAISY software (BrukerÒ), allowed to determine the coupling constants of 2b and 2c, which are reported in the experimental part. All these spectroscopic data were consistent with literature information concerning crown and thiacrown ethers.24,27 In addition, highresolution mass spectrometry confirmed the formation of discrete crown oxathioethers 2aec. Slow evaporation of a solution of compound 2b in dichloromethane at rt gave crystals suitable for X-ray diffraction analysis. The asymmetric unit contains two independent but similar molecules, for clarity only one of them is shown in Fig. 2. The CeS (1.806e1.817 A), CeO (1.420e1.431 A), and CeC (1.500e1.512 A) bond lengths are consistent with average values related to ethers and thioethers compounds.28 The C1eC2 double bound has a normal length of 1.318 A.29 General conformation mostly follows the rules established by Wolf et al.25 for rationalizing the structure of crown oxathioethers: torsion angles of CeCeSeC chains from 48 to 73 are close to the gauche arrangement (60 ) and those of SeCeCeS chains of 166 are closed to anti angle (180 ). Subsequently, calculated distances between two sulfur atoms in thioether units ranged from 4.4 to 4.6 A thus matching previously published data.28 However, only half of CeO bounds present dihedral angles of 175e176 close to predicted anti angles, while the other ones present gauche-like torsion angles (72e73 ). Since these abnormal values concerned the bonds close to the
Fig. 1. Above: computational 1H NMR spectra for selected protons in compounds 2b and 2c (298 K). Below: experimental 1H NMR signals of selected protons in compounds 2aec.
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Fig. 2. Molecular structure of compound 2b in the solid state (ellipsoids set at 50% probability). For clarity, only one of the two independent molecules of the asymmetric unit is shown and hydrogen atoms are omitted. Selected bond distances [ A], bond angles [ ], and torsion angles [ ]: C1eC2 1.318(4), C2eC3 1.499(4), C4eC5 1.500(4), O1eC3 1.428(3), O1eC4 1.425(3), S1eC5 1.806(3), S1eC6 1.817(3), C1eC2eC3 121.9(3), C3eO1eC4 112.6(2), C5eS1eC6 105.2(2), C2eC3eO1eC4 72.7(3), C3eO1eC4eC5 176.3(2), O1eC4eC5eS1 68.4(3), C4eC5eS1eC6 72.6(2), C5eS1eC6eC7 47.5(2), S1eC6eC7eS2 166.1(2), C6eC7eS2eC8 55.3(2), C7eS2eC8eC9 58.4(2).
alkene function, the rigidity induced by the double bond from C1 to C12 must be responsible for these deviations from ideal conformation. Exocyclic double-bond can be directly grafted on a polysiloxane,20 but its main interest is to allow the access of various functional groups. Tomoi et al. showed that ketone and alcohol functions may be easily obtained from alkene crown ethers in moderate to good yields (60e90%).23 In order to facilitate further reactions on hydroxyl group, we decided to prepare the less hindered primary alcohols, thus hydroborationeoxidation procedure was chosen. This two-step reaction is very efficient for selective oxidation of double bonds,30 and has successfully been applied to the synthesis of hydroxyl crown ether.23 The preparation of organoborane was achieved by action of lithium borohydride in acidic conditions in tetrahydrofuran and followed by in situ oxidative workup (Scheme 2).
Scheme 2. Synthesis of crown oxathioethers 3aec.
Preliminary assays showed that stoichiometric conditions left a high proportion of starting materials 2aec so an excess of reactants was used at both steps to achieve full conversion. After column chromatography on silica gel, pure crowns oxathioethers were isolated as white solid (3a) or thick uncolored oils (3b,c) in 67%, 45%, and 37% yields, respectively. Besides the characteristic signals of the CH2OH group, a complex set of signals in the 1H NMR spectra should be noted, which consists in overlapped multiplet signals for non-equivalent hydrogen atoms of the methylene groups. Indeed, due to the presence of a pendant arm CH2OH, the intracyclic CH2O protons are non-equivalent generating second-order spin systems (Fig. 3): ABX system for H(c) protons with H(b), ABXY system appearing as pseudo-triplets for H(d) and H(e) protons. Slow recrystallization of 3a in chloroform gave suitable crystals for X-ray diffraction analysis. The asymmetric unit contains two molecules, for clarity only one of them is represented in Fig. 4.
Fig. 3. Experimental (solid line) and computational (dotted line) 1H NMR signals of selected protons of 3a.
Fig. 4. Molecular structure of compound 3a in the solid state (ellipsoids set at 50% probability). For clarity, only one of the two independent molecules of the asymmetric unit is shown and hydrogen atoms are omitted. Selected bond distances [ A], bond angles [ ], and torsion angles [ ]: C1eC2 1.519(6), C2eC3 1.586(8), C4eC5 1.516(9), O1eC1 1.425(6), O2eC3 1.414(9), O2eC4 1.443(8), S1eC5 1.804(7), S1eC6 1.818(8), C1eC2eC3 107.5(5), C3eO2eC4 113.8(5), C5eS1eC6 104.0(4), C2eC3eO2eC4 173.4(5), C3eO2eC4eC5 81.9(8), O2eC4eC5eS1 74.7(7), C4eC5eS1eC6 79.0(6), C5eS1eC6eC7 53.0(8), S1eC6eC7eS2 156.4(6).
As observed for 2b, the CeS (1.804e1.833 A), CeO (1.409e1.443 A), and CeC (1.488e1.586 A) bond lengths are consistent with comparable literature values.28 The C1eO1 bound length of 1.425 A lies within the expected range31 as well as the distance of 4.332 A between S1 and S2.28 This structure is moderately constrained with significant deviations from the ideal conformation:25 SeCeCeS and CeCeSeC torsion angles have the awaited order of magnitude with distortion from 7 to 19 from theoretical values, but some CeCeOeC torsion angles are strongly distorted, with variations up to 103 from the expected anti angle (180 ). In contrast with 2a where the observed distortions are clearly related to the presence of the double bond, 3a shows constraint mainly in the region between the oxygen and the sulfur atoms.
2.2. Hydroxy crown oxathioethers reactivity Applications could also require the crown macrocycle to have specific chemical or physical properties. The presence of a hydroxyl group offers the possibility to access to a lot of functionalized
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macrocycles by nucleophilic substitution reaction of a halide substrate. This is a very common route in the crown ether series,32e34 which has been rarely applied to crown oxathioethers.15 This prompted us to carry out some experiments on hydroxyl crown oxathioether 3a. Sodium hydride is known to be a Brønsted base compatible with cyclic ethers and thioethers.15 We used it to prepare the alkoxide salt from alcohol 3a in tetrahydrofuran at 50 C. The reaction with triethylene glycol 2-bromoethyl methylether or benzyl bromide leads to functionalized crown oxathioethers 4a and 4b, respectively (Scheme 3). After column chromatography pure compounds 4a and 4b were isolated as pale yellow oils (23 and 85% yields, respectively).
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2.3. Coordination properties The ability of these functionalized macrocycles to coordinate to a soft transition metal and more particularly to palladium was investigated. When using the same procedure used for the preparation of 6a38 namely reaction of stoichiometric amounts of 2a and PdCl2 in refluxing water/methanol solution, the corresponding complexes 6 were obtained in yields ranging from 36% to quantitative (Scheme 5). The coordination reactions using 2c and the bicyclic compounds 5a and 5b as ligands are more complex and led to a mixture of compounds that could not be identified.
Scheme 3. Synthesis of crown oxathioethers 4a,b. Scheme 5. Preparation of complexes 6.
The good yield obtained with benzyl chloride encouraged us to prepare new bicyclic sandwich-type molecules from the reaction of 1,2- or 1,3-dibromoxylene and 2 equiv of crown oxathioether 3a (Scheme 4) in the same experimental conditions. After column chromatography bicyclic compounds 5a and 5b were isolated as pale yellow oils in good yields (72%).
Fig. 5 shows the structure of 6b with selected bond lengths and angles. The main feature is the coordination of the palladium center to two S neighboring atoms from the macrocycle 2b with the two Cl atoms occupying the two other binding sites, the Pd(II) atom exhibiting a cis-type square planar geometry and the third sulfur and the two oxygen atoms remaining uncoordinated.
Scheme 4. Synthesis of bicyclic compounds 5a,b.
Comparison of 1H and 13C NMR spectra of 4a,b and 5a,b showed little difference in the crown oxathioether part of the molecule, so substitution by aryl group or polyether chain did not affect the structure of the macrocycle. The new functions were fully characterized in 1H and 13C NMR for 4a (polyether units) and for 4b and 5a,b (benzylic carbon and aryl group), showing chemical shifts consistent with comparable available experimental data.35 Alcohol conversion has been confirmed by the disappearance of OeH bound in infra-red spectra. The expected compounds were also characterized by high-resolution mass spectrometry. These new compounds present some interesting features compared to the hydroxyl crown oxathioether 3a. The long polyether chain grafted on 4a gives it a better affinity for polar solvents and makes it perfectly soluble in water medium whereas 3a was only slightly soluble in ethanol. Bicyclic compounds 5a,b bearing two crown ethers instead of oxathioethers are expected to present higher coordination properties than the mono-macrocycle derivatives, especially for the preparation of 1:2 ‘sandwich-like’ metaleligand complexes.36 This property can be applied for the extraction of cations in solutions.37
Fig. 5. Molecular structure of compound 6b in the solid state (ellipsoids set at 50% probability). The asymmetric unit contains two crystallographically independent molecules, only one of them is shown. For clarity, hydrogen atoms are omitted. Selected bond distances [ A] and bond angles [ ]: Pd(1)eS(1) 2.264(1), Pd(1)eS(2) 2.260(1), Pd(1)eCl(1) 2.320(1), Pd(1)eCl(2) 2.328(1); Cl(1)ePd(1)eCl(2) 95.07(3), Cl(1)ePd(1)eS(2) 174.50(3), Cl(1)ePd(1)eS(1) 86.66(3), Cl(2)ePd(1)eS(2) 89.65(3), Cl(2)ePd(1)eS(1) 178.11(3), S(2)ePd(1)eS(1) 88.59(3).
Concerning complexes 6c and 6d, two isomeric structures were identified by 1H NMR in 55:45 ratio. Slow evaporation of a solution of the mixture of these isomers for 6d in chloroform at rt gave monocrystals suitable for X-ray diffraction analysis and showing a co-crystallization of the two isomeric structures (Fig 6). Except the position of the hydrogen atom pointing up or down the cycle,
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two isomeric forms could be isolated with the hydroxy and benzyloxy substituted macrocyles. 4. Experimental section 4.1. General methods
Fig. 6. Molecular structures of compound 6d in the solid state (ellipsoids set at 50% probability). For clarity, the two isomeric structures are drawn separately (only atoms Pd1, S1, S2, Cl1, and Cl2 are not disordered). Hydrogen atoms are omitted. Selected bond distances [ A] and bond angles [ ]: Pd(1)eS(1) 2.258(1), Pd(1)eS(2) 2.273(2), Pd(1)eCl(1) 2.330(2), Pd(1)eCl(2) 2.315(2); Cl(1)ePd(1)eCl(2) 92.82(4), Cl(1)ePd(1)e S(2) 177.42(4), Cl(1)ePd(1)eS(1) 89.25(4), Cl(2)ePd(1)eS(2) 89.20(4), Cl(2)ePd(1)e S(1) 176.96(4), S(1)ePd(1)eS(2) 88.67(4).
the major difference lies in the deformation of the macrocycle with different torsion angles S(1)eCeCeS(2) of 47.78 and 60.72 indicating a strongly folded cycle for one isomer. As a result a large variation is observed between the O(1)eO(2) (2.951 A) and O(10 )e 0 O(2 ) (3.627 A) bond distances. The PdeS bond lengths (2.264(1), 2.260(1) A in 6b and 2.258(1), 2.273(2) A in 6d) are in the range of those previously observed in cis-Cl2S2-type Pd(II) complexes.7b,g,h,j,12 The 1H NMR spectra of complexes 6bed are almost identical in the aliphatic area except for the functional groups confirming the formation of similar 1:1 complexes. The greatest downfield shifts were observed for the methylene groups attached to sulfur atoms in agreement with the coordination of sulfur atoms to the palladium center. The coordination behavior of these macrocycles is similar in many respects to that of the two sulfur containing unsaturated ligand 2a. In each case, the exo-coordination was obtained with the formation of 1:1 complexes.
3. Conclusion New mixed functionalized oxathioethers macrocycles and new bicyclic sandwich-type derived compounds have been synthesized and characterized. These various macrocycles containing two ether bridges and 2e4 thioether bridges have been obtained by condensation reaction from dianions of thioethers diols with 3-chloro2-chloromethylprop-1-ene, then hydroboration/oxidation of the exocyclic double-bond. X-ray diffraction structures of macrocycle 2b functionalized by an exocyclic double-bond and macrocycle 3a substituted by a methyl hydroxyl group have been determined. The reactivity of the primary hydroxyl group upon halide compounds has been exploited through nucleophilic substitution, confirming the interest of these primary alcohols as customizable crown macrocycles. In this way properties like solvent solubility or spectroscopic properties can be adjusted to application requirement with no impact on the coordinating part of the molecule. Experiments involving affinity between these new macrocycles and palladium(II) have been investigated and afforded the corresponding exo-coordinated 1:1 complexes with the two S-donor atoms, and
All manipulations with air-sensitive materials were performed in a dry and oxygen-free atmosphere of argon by using standard schlenk-line. Solvents were purified with an MBRAUN SBS-800 purification system. NMR spectra were recorded in CDCl3 on a Bruker Avance II 300: 1H (300.18 MHz), 13C (75.48 MHz) at 298 K. Chemical shifts are expressed in parts per million (ppm) with residual solvent signals as internal standard. Mass spectrometry (MS) spectra were measured with a HewlettePackard 5989A in the electron impact mode (70 eV). High-resolution mass spectrometry (HRMS) spectra were measured with a GCT Premier Waters in DCI mode (CH4). IR spectra were measured on a Varian 640-IR FT-IR spectrometer. Melting points were measured with a sealed capillary using a Stuart automatic melting point SMP40 apparatus. Elemental analyses were realized by the central analysis service department of the Institut des Sciences Analytiques (ISA, UMR 5280) from Solaize or by the microanalysis service of the Laboratoire de Chimie de Coordination (LCC, UPR 8241) from Toulouse. Thin layer chromatographies (TLC) were performed over silica gel (Si60-F254, Merck). Column chromatographies were performed over silica gel (Si60 35e70 mm, SDS) and followed by TLC. 3,6Dithiaoctane-1,8-dithiol and 3-chloro-2-chloromethyl-1-propene were purchased from Acros. Thioether diols 1b,c were synthesized by following literature procedures.25 4.2. Syntheses of crown oxathioethers 4.2.1. 12-Methylene-1,10-dioxa-4,7-dithiacyclotridecane (2a).38 To a suspension of sodium hydride (90 mmol) in refluxing tetrahydrofuran (600 mL) were simultaneously added for 3e4 h 3,6-dithia1,8-octanediol (5.52 g, 30 mmol) and 3-chloro-2-chloromethyl-1propene (3.88 g, 31 mmol) solubilized in tetrahydrofuran (60 mL). After stirring for 16 h, the mixture was cooled, water (30 mL) was slowly added and the solvent was evaporated under reduced pressure. The aqueous layer was neutralized by hydrogen chloride solution (6 N), then extracted with dichloromethane (430 mL). Dichloromethane was evaporated under reduced pressure then the resulting solid was solubilized in dichloromethane/ethyl acetate (80:20) and filtered on silica gel. Solvent was removed from filtrate and the resulting orange solid was purified by column chromatography (dichloromethane/ethyl acetate, 95:5) to obtain product 2a as a yellow oil (Rf¼0.68, 14e17% yield). 1H NMR (CDCl3, 300 MHz): d 5.25 (t, 4J¼0.6 Hz, 2H, ]CH2), 4.06 (s, 4H, CH2eC]), 3.78 (t, 3J¼5.5 Hz, 4H, SeCH2eCH2eO), 2.95 (s, 4H, SeCH2eCH2eS), 2.77 (t, 3J¼5.5 Hz, 4H, SeCH2eCH2eO). 13C NMR (CDCl3, 300 MHz): d 143.0 (C]CH2), 117.8 (C]CH2), 72.5 (SeCH2eCH2eO), 72.4 (CH2eC]), 32.9 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3070, 2962, 2906, 1645, 1412, 1261, 1095, 1044, 865, 702. GCeMS (in CH2Cl2): m/z [M]þ¼234 (4%); [M(CH2CH2)]þ¼206 (3%), [M(CH2CH2O)þ1]þ¼191 (3%); [M(CH2CH2SCH2CH2)þ 1]þ¼147 (6%). HRMS (CI/CH4): [Mþ1] calcd for C10H19O2S2: 235.0826. Found: 235.0837. 4.2.2. 15-Methylene-1,13-dioxa-4,7,10-trithiacyclohexadecane (2b). A solution of 3,6,9-trithia-1,11-undecanediol (3.64 g, 15.0 mmol) and sodium (0.93 g, 40.0 mmol) in 1,4-dioxane (300 mL) was heated to reflux for 3 h to obtain the disodium salt as a pale brown solid. Then a solution of 3-chloro-2-chloromethyl-1-propene (1.88 g, 15.0 mmol) in 1,4-dioxane (150 mL) was added for 3 h in the refluxing suspension, then the mixture was stirred overnight. Water
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(15 mL) was slowly added at rt then the solvents were removed under reduced pressure. The residue was treated with water (15 mL) then extracted with dichloromethane (320 mL). After solvent evaporation, the resulting amber solid was vigorously extracted with diethyl ether (450 mL). The oil was purified by column chromatography (dichloromethane/ethyl acetate, 95:5) to obtain pure product as a yellow viscous oil (Rf¼0.74; 0.79 g, 17% yield). Crystals suitable for X-ray analysis were obtained by crystallization in dichloromethane. 1H NMR (CDCl3, 800 MHz): d 5.20 (quint, 4J¼0.4 Hz, 2H, ]CH2), 4.10 (t, 4J¼0.9 Hz, 4H, CH2eC]), 3.65 (t, 3 J¼6.0 Hz, 4H, SeCH2eCH2eO), 2.88 (AA0 BB0 syst., 2JAA0 ¼13.6 Hz, 3 JAB0 ¼3JA0 B¼11.0 Hz, 3JAB¼3JA0 B0 ¼5.2 Hz, 4H, SeCH2eCH2eS eCH2eCH2eO), 2.80 (AA0 BB0 syst., 2JBB0 ¼13.1 Hz, 3JAB0 ¼3JA0 B¼11.0 Hz, 3 JAB¼3JA0 B0 ¼5.2 Hz, 4H, SeCH2eCH2eSeCH2eCH2eO), 2.74 (t, 3 J¼6.0 Hz, 4H, SeCH2eCH2eO). 13C NMR (CDCl3, 75 MHz): d 143.0 (C]CH2), 116.0 (C]CH2), 71.5 (CH2eC]), 71.3 (SeCH2eCH2eO), 32.8 (SeCH2eCH2eS), 31.5 (SeCH2eCH2eO, SeCH2eCH2eS). IR (pure): n (cm1) 3074, 2914, 2851, 1655, 1423, 1265, 1199, 1098, 1044, 919, 718. MS (EI: 70 eV): m/z [M]þ¼294 (2%); [M(CH2CH2S)]þ¼233 (3%); [M((CH2CH2)2S)]þ¼206 (2%); [M((CH2CH2S)2)]þ¼174 (10%). HRMS (CI/CH4): [Mþ1] calcd for C12H23O2S3: 295.0860. Found: 295.0863. 4.2.3. 18-Methylene-1,16-dioxa-4,7,10,13-tetrathiacyclononadecane (2c). A solution of 3,6,9,12-tetrathia-1,14-tetradecanediol (1.51 g, 5.0 mmol) and sodium (0.31 g, 13.3 mmol) in 1,4-dioxane (100 mL) was heated at reflux for 2 h to obtain the disodium salt as a solid. A solution of 3-chloro-2-chloromethyl-1-propene (0.63 g, 5.0 mmol) in 1,4-dioxane (50 mL) was added at 80 C for 30 min then the mixture was heated at reflux and stirred overnight. 1,4-Dioxane was removed under reduced pressure and the resulting solid was extracted with dichloromethane (3100 mL). After solvent evaporation, the resulting brown solid was vigorously extracted by diethyl ether (325 mL). The oil was then purified by column chromatography (dichloromethane/ethyl acetate, 95:5) to obtain pure product as a yellow oil (Rf¼0.60; 0.29 g, 16% yield). 1H NMR (CDCl3, 300 MHz): d 5.23 (s, 2H, ]CH2), 4.08 (s, 4H, CH2eC]), 3.68 (t, 3J¼6.0 Hz, 4H, SeCH2eCH2eO), 2.89 (AA0 BB0 syst., 2JAA0 ¼13.6 Hz, 3 JAB0 ¼3JA0 B¼10.5 Hz, 3JAB¼3JA0 B0 ¼5.6 Hz, 4H, SeCH2eCH2eSeCH2e CH2eO), 2.84 (AA0 BB0 syst., 2JBB0 ¼13.6 Hz, 3JAB0 ¼3JA0 B¼10.5 Hz, 3 JAB¼3JA0 B0 ¼5.6 Hz, 4H, SeCH2eCH2eSeCH2eCH2eO), 2.82 (s, 4H, 3 SeCH2eCH2eSeCH2eCH2eS), 2.78 (t, J¼6.0 Hz, 4H, SeCH2eCH2eO). 13C NMR (CDCl3, 75 MHz): d 142.5 (C]CH2), 115.3 (C]CH2), 71.7 (CH2eC]), 71.2 (SeCH2eCH2eO), 33.3, 32.8 (SeCH2eCH2eSeCH2eCH2eO), 32.7 (SeCH2eCH2eSeCH2eCH2 eS), 32.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3073, 2914, 2851, 1655, 1423, 1266, 1200, 1098, 1043, 919, 719. MS (EI: 70 eV in CH2Cl2): m/z [M]þ¼354 (5%); [M(CH2CH2S)2]þ¼234 (3%); [M(CH2CH2S)2]þ¼174 (13%). HRMS (CI/CH4): [Mþ1] calcd for C14H27O2S4: 355.0894. Found: 355.0887. 4.3. General procedure for hydroborationeoxidation reactions (3aec) Lithium borohydride (4 M soln in THF, 0.35 mL, 1.4 mmol) then hydrogen chloride (2 M soln in diethyl ether, 1.0 mL, 2 mmol) were added to as solution of 2aec alkene macrocycle (1 mmol) in tetrahydrofuran (4 mL). The mixture was stirred for 1 h and water (0.4 mL) then sodium hydroxide solution (10 mol/L soln in water, 16 mmol) were slowly added. Hydrogen peroxide (30% w/w in water, 0.8 mL, 7 mmol) was added and the mixture was stirred for 1 h. The mixture was diluted by addition of THF (10 mL) and a sodium chloride solution (150 g/L, 10 mL) was added. The organic layer was separated by decantation, washed by saturated sodium chloride aqueous solution (5 mL), and dried on sodium sulfate. Solvents were removed in vacuo. Crude product was purified by
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column chromatography (dichloromethane/ethyl acetate, 1:1) to obtain the corresponding alcohol. 4.3.1. (1,10-Dioxa-4,7-dithiacyclotridecan-12-yl)methanol (3a). White solid gum (Rf¼0.40 [dichloromethane/ethyl acetate, 1:1], 67% yield). Crystals suitable for X-ray analysis were obtained by crystallization in chloroform. Mp¼50 C. 1H NMR (CDCl3, 300 MHz): d 3.83 (pseudo-t, J¼4.7 Hz, 4H, SeCH2eCH2eO), 3.76 (d, 3 J¼4.6 Hz, 2H, CH2eOH), 3.74 (dd, 2H, 2J¼9.3 Hz, 3J¼4.1 Hz, OeCHH0 eCH), 3.68 (dd, 2H, 2J¼9.3 Hz, 3J¼6.4 Hz, OeCHH0 eCH), 2.96 (s, 4H, SeCH2eCH2eS), 2.74 (pseudo-t, J¼4.7 Hz, 4H, SeCH2eCH2eO), 2.22 (br s, 1H, OH), 2.07e1.96 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d 74.2 (SeCH2eCH2eO), 69.5 (OeCH2eCH), 63.7 (CH2eOH), 41.8 (CH), 33.6 (SeCH2eCH2eS), 31.3 (SeCH2eCH2eO). IR (pure): n (cm1) 3430, 2911, 2860, 1479, 1405, 1368, 1276, 1115, 1031, 715. MS (EI: 70 eV): m/z [M]þ¼252 (10%); [MCH2CH2S]þ¼193 (25%); [M(CH2CH2S)2]þ¼133 (11%). Anal. Calcd for C10H20O3S2: C, 47.59; H, 7.99. Found: C, 47.22; H, 6.16%. 4.3.2. (1,13-Dioxa-4,7,10-trithiacyclohexadecan-15-yl)methanol (3b). Thick uncolored oil (Rf¼0.45 [dichloromethane/ethyl acetate, 1:1], 45% yield). 1H NMR (CDCl3, 300 MHz): d 3.74 (d, 3J¼5.1 Hz, 2H, CH2eOH), 3.67 (pseudo-t, 4H, 3J¼6.4 Hz, SeCH2eCH2eO), 3.72e3.60 (m, 4H, OeCH2eCH), 2.91e2.74 (m, 8H, SeCH2eCH2eS), 2.75 (t, 3J¼6.4 Hz, 4H, SeCH2eCH2eO), 2.46 (br s, 1H, OH), 2.10e2.03 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d 71.6 (SeCH2eCH2eO), 70.0 (OeCH2eCH), 63.6 (CH2eOH), 41.7 (CH), 32.7, 31.9 (SeCH2eCH2eS), 31.5 (SeCH2eCH2eO). IR (pure): n (cm1) 3440, 2916, 2865, 1462, 1423, 1364, 1261, 1094, 1032. MS (EI: 70 eV): m/z [M]þ¼312 (1%); [M(CH2CH2S)]þ¼253 (3%); [M(CH2CH2S)2]þ¼193 (3%). Anal. Calcd for C12H24O3S3: C, 46.12; H, 7.74. Found: C, 45.80; H, 7.84%. 4.3.3. (1,16-Dioxa-4,7,10,13-tetrathiacyclononadecan-18-yl)methanol (3c). Thick uncolored oil (Rf¼0.52 [dichloromethane/ethyl acetate, 1:1], 37% yield). 1H NMR (CDCl3, 300 MHz): d 3.78 (d, 3 J¼4.9 Hz, 2H, CH2eOH), 3.68 (t, 3J¼6.4 Hz, 4H, SeCH2eCH2eO), 3.72e3.60 (m, 4H, OeCH2eCH), 2.83 (br s, 12H, SeCH2eCH2eS), 2.76 (t, 3J¼6.4 Hz, 4H, SeCH2eCH2eO), 2.52 (s, 1H, OH), 2.14e2.07 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d 71.7 (SeCH2eCH2eO), 70.5 (OeCH2eCH), 63.9 (CH2eOH), 41.6 (CH), 33.1, 32.8, 32.7 (SeCH2eCH2eS), 32.0 (SeCH2eCH2eO). IR (pure): n (cm1) 3450, 2914, 2863, 1459, 1423, 1365, 1264, 1105, 1036, 715. MS (EI: 70 eV): m/z [M]þ¼372 (0.3%); [M(CH2CH2S)]¼313 (2%); [M(CH2CH2S)2]þ¼252 (3%); [M(CH2CH2S)3]þ¼193 (5%). Anal. Calcd for C14H28O3S4: C, 45.13; H, 7.57. Found: C, 45.72; H, 7.54%. 4.4. Reactivity of hydroxy crown oxathioethers 4.4.1. 12-(2,5,8,11,14-Pentaoxapentadecyl)-1,10-dioxa-4,7dithiacyclotridecane (4a). Sodium hydride (60% w/w in mineral oil, 40 mg, 1.0 mmol) washed by pentane (310 ml) was suspended at 0 C in tetrahydrofuran (3 mL), then alcohol 3a (127 mg, 0.5 mmol) in tetrahydrofuran (2 mL) was slowly added. The suspension was slowly warmed at rt and stirred for 1 h, then triethylene glycol, 2bromoethyl methyl ether (160 mL, 0.8 mmol) were added. After 1 h at rt the mixture was stirred at 50 C for 48 h. Water (2.5 mL) was slowly added then saturated sodium chloride solution (2.5 mL) was added and tetrahydrofuran phase was recovered by decantation. Aqueous phase was extracted by dichloromethane (35 mL) then organic phases were combined and dried on sodium sulfate. Solvents were removed under reduced pressure and crude product was purified by column chromatography (dichloromethane/ethyl acetate 1:1) to afford pure product as pale yellow oil (Rf¼0.14, 50 mg, 23% yield). 1H NMR (CDCl3, 300 MHz): 3.82e3.70 (m, 4H, SeCH2eCH2eO), 3.70e3.44 (m, 22H, CH2eOH, OeCH2eCH,
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[CH2CH2eO]4), 3.37 (s, 3H, OCH3), 2.94 (br s, 4H, SeCH2eCH2eS), 2.73e2.65 (m, 4H, SeCH2eCH2eO), 2.23e2.10 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): 74.2 (SeCH2eCH2eO), 71.9 (CH2eOH), 70.63, 70.60, 70.56, 70.54, 70.50, 70.4 ([CH2CH2eO]4), 69.3 (OeCH2eCH), 59.1 (OCH3), 40.4 (CH), 33.4 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 2908, 2866, 1455, 1405, 1290, 1259, 1353, 1107, 1036, 715. MS (EI: 70 eV): m/z [M]þ¼443 (1%); [M(CH2CH2OCH3)]þ¼383 (3%); [M(OCH2CH2)2OCH3]þ¼323 (1%). HRMS (CI/CH4): calcd for C19H39O7S2: 443.2137. Found: 443.2142. 4.4.2. 12-(Benzyloxymethyl)-1,10-dioxa-4,7-dithiacyclotridecane (4b). Sodium hydride (60% w/w in mineral oil, 40 mg, 1.0 mmol) washed by pentane (310 ml) was suspended at 0 C in tetrahydrofuran (3 mL), then alcohol 3a (130 mg, 0.5 mmol) in tetrahydrofuran (2 mL) was slowly added. The suspension was slowly warmed at rt and stirred for 1 h, and then benzyl bromide (90 mL, 0.8 mmol) was added. After 1 h at rt the mixture was stirred at 50 C until TLC (dichloromethane/ethyl acetate, 1:1) had showed full disappearance of reactant 3a. Water (2.5 mL) was slowly added then saturated sodium chloride aqueous solution (2.5 mL) was added and tetrahydrofuran phase was recovered by decantation. Aqueous phase was extracted by dichloromethane (35 mL) then organic phases were combined and dried on sodium sulfate. Solvents were removed under reduced pressure to afford pure product as pale yellow oil (146 mg, 85% yield). 1H NMR (CDCl3, 300 MHz): 7.45e7.25 (m, 5H, C6H5), 4.53 (s, 2H, CH2Ph), 3.87e3.71 (m, 4H, SeCH2eCH2eO), 3.67 (dd, 2J¼9.0 Hz, 3J¼3.6 Hz, 2H, OeCHH0 eCH), 3.55 (dd, 2J¼9.0 Hz, 3J¼7.1 Hz, 2H, OeCHH0 eCH), 3.50 (d, 2J¼6.7 Hz, 2H, CHeCH2eOBn), 3.03e2.93 (m, 4H, SeCH2eCH2eS), 2.76e2.69 (m, 4H, SeCH2eCH2eO), 2.28e2.20 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): 138.4 (Cipso), 128.5 (Cm), 127.7 (Cp), 127.6 (Co), 74.3 (SeCH2eCH2eO), 73.2 (CH2Ph), 69.43, 69.38 (CHeCH2eOBn, OeCH2eCH), 40.6 (CH), 33.5 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3300e3000, 2912, 2856, 1453, 1404, 1366, 1263, 1204, 1094, 850, 698. MS (EI: 70 eV): m/z [M]þ¼342 (1%); [M(CH2CH2S)]þ¼283 (1%); [M(CH2CH2S) OBn]þ¼176 (3%). HRMS (CI/CH4): [Mþ1] calcd for C17H27O3S2: 343.1402. Found: 343.1400. 4.5. General procedure for synthesis of bicyclic compounds (5a,b) Sodium hydride (60% w/w in mineral oil, 46 mg, 1.2 mmol) washed by pentane (310 ml) was suspended at 0 C in tetrahydrofuran (2 mL), then alcohol 3a (128 mg, 0.5 mmol) in tetrahydrofuran (2 mL) was slowly added. The suspension was slowly warmed at rt and stirred for 1 h, then 1,2- and 1,3bis(bromomethyl)benzene (66 mg, 0.25 mmol) in tetrahydrofuran (1 mL) was added. The mixture was stirred at 50 C until TLC (dichloromethane/ethyl acetate, 1:1) had showed full disappearance of reactant 3a (16 h). Water (2.5 mL) then saturated sodium chloride aqueous solution (2.5 mL) was added and tetrahydrofuran phase was recovered by decantation. Aqueous phase was extracted by dichloromethane (35 mL) then organic phases were combined and dried on sodium sulfate. Solvents were removed and the orange solid was purified by column chromatography (dichloromethane/ethanol 96:4) to afford pure product 5a or 5b as yellow oil. 4.5.1. 1,2-Bis[((1,10-dioxa-4,7-dithiacyclotridecan-12-yl)methoxy) methyl]benzene (5a). Yellow oil (Rf¼0.48 [dichloromethane/ethanol 96:4], 110 mg, 72% yield). 1H NMR (CDCl3, 300 MHz): 7.40e7.38 (m, 2H, CoH), 7.33e7.30 (m, 2H, CmH), 4.57 (s, 4H, CH2Ar), 3.85e3.72 (m, 8H, SeCH2eCH2eO), 3.66 (dd, 2J¼9.0 Hz, 3J¼3.6 Hz, 4H, OeCHH0 eCH), 3.54 (dd, 2J¼9.0 Hz, 3J¼7.1 Hz, 4H, OeCHH0 eCH),
3.50 (d, 2J¼6.7 Hz, 4H, CHeCH2eO), 2.97 (s, 8H, SeCH2eCH2eS), 2.74e2.71 (m, 8H, SeCH2eCH2eO), 2.30e2.15 (m, 2H, CH). 13C NMR (CDCl3, 75 MHz): 136.4 (Cipso), 128.7 (Co), 127.9 (Cm), 74.3 (SeCH2eCH2eO), 70.9 (CH2Ar), 69.6 (CHeCH2eO), 69.4 (OeCH2eCH), 40.6 (CH), 33.5 (SeCH2eCH2eS), 31.3 (SeCH2eCH2eO). IR (pure): n (cm1) 3040, 2913, 2859, 1455, 1404, 1367, 1268, 1205, 1116, 1189, 1044. MS (EI: 70 eV): m/z [M]þ¼606 (1%); [M(CH2CH2S)2]þ¼487 (0.5%); [M(3a)]þ¼354 (6%). HRMS (CI/CH4): [Mþ1] calcd for C28H47O6S4: 607.2256. Found: 607.2280. 4.5.2. 1,3-Bis[((1,10-dioxa-4,7-dithiacyclotridecan-12-yl)methoxy) methyl]benzene (5b). Yellow oil (Rf¼0.60 [dichloromethane/ethanol 96:4], 109 mg, 72% yield). 1H NMR (CDCl3, 300 MHz): 7.40e7.27 (m, 4H, C6H4), 4.53 (s, 4H, CH2Ar), 3.84e3.73 (m, 8H, SeCH2eCH2eO), 3.67 (dd, 2J¼9.0 Hz, 3J¼3.6 Hz, 4H, OeCHH0 eCH), 3.55 (dd, 2J¼9.0 Hz, 3J¼7.1 Hz, 4H, OeCHH0 eCH), 3.51 (d, 2J¼6.7 Hz, 4H, CHeCH2eO), 2.98 (s, 8H, SeCH2eCH2eS), 2.75e2.71 (m, 8H, SeCH2eCH2eO), 2.28e2.20 (m, 2H, CH). 13C NMR (CDCl3, 75 MHz): 138.5 (Cipso), 128.6 (Cm), 126.9, 126.7 (Co), 74.2 (SeCH2eCH2eO), 73.1 (CH2Ar), 69.5 (CHeCH2eO), 69.3 (OeCH2eCH), 40.6 (CH), 33.4 (SeCH2eCH2eS), 31.2 (SeCH2eCH2eO). IR (pure): n (cm1) 3026, 2913, 2857, 1457, 1404, 1366, 1274, 1204, 1100e1092, 1041. MS (EI: 70 eV): m/z [M(CH2CH2S)2]þ¼487 (1%); [M(3a)]þ¼354 (15%). HRMS (CI/CH4): [Mþ1] calcd for C28H47O6S4: 607.2256. Found: 607.2269. 4.6. Synthesis of palladium complexes 4.6.1. Complex[Pd(2b)Cl2] (6b). Macrocycle 2b (56 mg, 0.2 mmol) was added to a suspension of palladium(II) dichloride (36 mg, 0.2 mmol) in a 1:1 methanol/water mixture (30 mL) and heated to reflux for 2 h. The orange solution was then filtered and the removal of solvents afforded compound 6b as an orange gum (quantitative yield). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a chloroform solution. 1H NMR (CDCl3, 300 MHz): d 5.28 and 5.23 (s, 21H, ]CH2), 4.70e2.60 (m, 20H, CH2). 13C NMR (CDCl3, 75 MHz): d 141.6 (C]CH2), 117.7 (C]CH2), 73.0 and 72.4 (SeCH2eCH2eO), 72.10 and 72.07 (CH2eC]), 38.9, 37.9, 37.4, 37.3 (SeCH2eCH2eS), 32.1, 31.2 (SeCH2eCH2eO, SeCH2eCH2eS). IR (pure): n (cm1) 2919, 2854, 1647, 1412, 1290, 1094, 1046, 849. MS FAB-(noba): m/z [MCl]þ¼437 (100%); [M2Cl]þ¼400 (26%). calcd for C12Cl2H22O2PdS3: C, 30.55; H, 4.70. Found: C, 30.35; H, 4.25. 4.6.2. Complex[Pd(3a)Cl2] (6c). Macrocycle 3a (50 mg, 0.2 mmol) was added to a suspension of palladium dichloride (38 mg, 0.2 mmol) in a 1:1 methanol/water mixture (30 mL) and refluxed for 2 h. After cooling to rt and evaporation of the solvents, the green residue was extracted with ethanol (40 mL then 25 mL). After filtration and evaporation of the ethanol in vacuo, compound 6c was isolated as yellow crystalline product (70 mg, 81% yield). Mp: 87 C. 1 H NMR (CD3CN, 300 MHz): d (Isomer 1, 55%): 4.47 (ddd, 2J¼11.3 Hz, 3 J¼8.9 Hz, 3J¼2.3 Hz, 2H, SeCH2CHH0 eO), 3.83 (ddd, 2J¼11.3 Hz, 3 J¼5.1 Hz, 3J¼2.5 Hz, 2H, SeCH2CHH0 eO), 3.85e3.60 (m, 2H, SeCHH0 eCHH0 eS), 3.75 (d, 3J¼4.6 Hz, 4H, OeCH2eCH) 3.53 (d, 3 J¼6.2 Hz, 2H, CH2OH), 3.42 (ddd, 2J¼14.9 Hz, 3J¼8.9 Hz, 3J¼2.5 Hz, 2H, SeCHH0 CH2eO), 3.07e2.90 (m, 2H, SeCHH0 eCHH0 eS), 2.90e2.73 (m, 2H, SeCHH0 CH2eO). d (Isomer 2, 45%): 4.39 (ddd, 2 J¼11.3 Hz, 3J¼8.7 Hz, 3J¼2.3 Hz, 2H, SeCH2CHH0 eO), 3.92 (ddd, 2 J¼11.3 Hz, 3J¼5.1 Hz, 3J¼3.0 Hz, 2H, SeCH2CHH0 eO), 3.85e3.75 (m, 2H, OeCHH0 eCH), 3.85e3.60 (m, 2H, SeCHH0 eCHH0 eS), 3.70e3.50 (m, 2H, OeCHH0 eCH), 3.48 (d, 3J¼6.2 Hz, 2H, CH2OH), 3.38 (ddd, 2 J¼14.9 Hz, 3J¼8.7 Hz, 3J¼2.4 Hz, 2H, SeCHH0 CH2eO), 3.07e2.90 (m, 2H, SeCHH0 eCHH0 eS), 2.90e2.73 (m, 2H, SeCHH0 CH2eO). Due to overlap with solvent peak at 2.2 ppm, the chemical shift of methane proton has not been determined. 13C NMR (CD3CN, 75 MHz): d (Isomer 1): 73.5 (OeCH2eCH), 70.8 (SeCH2CH2eO), 61.5
G. Carel et al. / Tetrahedron 70 (2014) 5650e5658
(CH2OH), 41.2 (CH), 39.8 (SeCH2CH2eS), 37.9 (SeCH2CH2eO). d (Isomer 2): 73.9 (OeCH2eCH), 71.1 (SeCH2CH2eO), 61.8 (CH2OH), 43.7 (CH), 40.1 (SeCH2CH2eS), 37.8 (SeCH2CH2eO). IR (KBr): n (cm1) 3480, 2923, 2854, 1465, 1261, 1126, 1097, 1029. MS FAB(noba): m/z 395 (73%) [MCl]þ, 358 (100%) [M2Cl]þ. 4.6.3. Complex[Pd(4b)Cl2] (6d). Macrocycle 4b (70 mg, 0.2 mmol) was added to a suspension of palladium dichloride (36 mg, 0.2 mmol) in a 1:1 methanol/water mixture (30 mL) and refluxed for 2 h. After evaporation of the solvents, the resulting orange solid was extracted with ethanol (50 then 220 mL) at 60 C. After filtration, ethanol was removed under vacuum. The residue was washed with diethyl ether (25 mL) and compound 6d was obtained as an orange powder (38 mg, 36% yield). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a chloroform solution. Mp: 72 C. 1H NMR (CDCl3, 300 MHz): d (Isomer 1, 55%): 7.44e7.30 (m, 5H, C6H5), 4.70e4.64 (m, 2H, SeCH2CHH0 eO), 4.54 (s, 2H, CH2Ph), 4.00e3.50 (m, 10H, OeCH2eCH, SeCH2CHH0 eO, SeCHH0 CH2eO, SeCHH0 eCHH0 eS), 3.51 (d, 2J¼6.9 Hz, 2H, CHeCH2OBn), 2.95e2.82 (m, 2H, SeCHH0 eCHH0 eS), 2.82e2.72 (m, 2H, SeCHH0 CH2eO), 2.40e2.20 (m, 1H, CH). d (Isomer 2, 45%): 7.44e7.30 (m, 5H, C6H5), 4.70e4.64 (m, 2H, SeCH2CHH0 eO), 4.51 (s, 2H, CH2Ph), 4.00e3.50 (m, 10H, OeCH2eCH, SeCH2CHH0 eO, SeCHH0 CH2eO, SeCHH0 eCHH0 eS), 3.40 (d, 2J¼6.0 Hz, 2H, CHeCH2OBn), 3.10e2.95 (m, 2H, SeCHH0 eCHH0 eS), 2.82e2.72 (m, 2H, SeCHH0 CH2eO), 2.30e2.20 (m, 1H, CH). 13C NMR (CDCl3, 75 MHz): d (Isomer 1) 138.0 (Cipso), 128.5 (Cm), 128.0, 127.8 (Co, Cp), 73.9 (OeCH2eCH), 73.2 (CH2Ph), 71.8 (SeCH2CH2eO), 68.4 (CHeCH2OBn), 39.7 (SeCH2CH2eS), 38.5 (CH), 38.0 (SeCH2CH2eO). d (Isomer 2): 138.4 (Cipso), 128.6 (Cm), 127.94, 127.90 (Co, Cp), 75.3 (OeCH2eCH), 73.5 (CH2Ph), 72.1 (SeCH2CH2eO), 69.4 (CHeCH2OBn), 41.5 (CH), 40.1 (SeCH2CH2eS), 38.2 (SeCH2CH2eO). IR (KBr): 3019, 2926, 2857, 1452, 1419, 1389, 1255, 1206, 1152, 1117, 849. MS FAB-(noba): m/z 485 (100%) [MCl]þ, 448 (66%) [M2Cl]þ. Anal. Calcd for C17H26Cl2O3PdS2: C, 39.28; H, 5.04. Found: C, 38.40; H, 4.61.
Supplementary data NMR spectroscopic data including 1H and 13C NMR spectra for compounds 2aec, 3aec, 4a,b, 5a,b and 6bed, and crystallographic data for 2b, 3a, 6b and 6d. This material is available free of charge via the internet. Supplementary data associated with this article can be found in the online version, at http://dx.doi.org/10.1016/ j.tet.2014.06.082.
References and notes 1. 2. 3. 4. 5.
6.
7.
4.7. X-ray crystallography The data of the structures for compounds 2b, 3a, 6b, and 6d were collected on a Bruker-AXS kappa APEX II Quazar diffractometer using a 30 W aircooled microfocus source (ImS) with focusing multilayer optics at a temperature of 193(2)K, with graphitemonochromated MoKa radiation (wavelength¼0.71073 A) by using 4- and u-scans. The data were integrated with SAINT,39 and an empirical absorption correction with SADABS40 was applied. The structures were solved by direct methods, using SHELXS-97 and refined using the least-squares method on F2.41 All non-H atoms were treated anisotropically. All H atoms attached to C atoms were fixed geometrically and treated as riding on their parent atoms. H atoms of OeH groups (3a) were located in difference Fourier maps and included in the subsequent refinement without using restraints. CCDC 969058 (2b), CCDC 969059 (3a), CCDC 1006504 (6b), and CCDC 908222 (6d), contain the supplementary crystallographic data. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif (or from the CCDC, 12 Union Road, Cambridge CB2 1EZ, UK; fax: þ44 1223 336 033; or [email protected]). Acknowledgements This work was supported by the Centre National de la Recherche de Toulouse and the Agence Scientifique (CNRS), the Universite Nationale pour la Recherche (ANR-08-CSOG-00). G.C. is grateful to the ANR for his Ph.D. grant and G.N. for 129/2008 PCCE grant.
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10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
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