- Email: [email protected]
X-Ray structure analyses of diphosphinidenecyclobutene and its chelate type tetracarbonylmolybdenum(O) complex
C35
Journal of Org~no~zeta~lic Chemistry, 431 (1992) C3S-C41 Elsevier Sequoia S.A., Lausanne
JOM 22766PC Preliminary communication -
X-Ray structure analyses of diphosphinidenecyclobutene and its chelate type tetracarbonylmolybdenum(0) complex Kozo Toyota, Katsuya Tashiro, Masaaki Yoshifuji Department
of Chemistry, Faculty of Science, Tohoku Unic>ersity,Aoha, Sendai 980 (Japan)
Ikuko Miyahara, Atsuhiro Hayashi and Ken Hirotsu Department of Chemistry, Faculty of Science, Osuka Cily lJnil,ersity, (Received
February
Sumiyoshi, Osaka 558 (Japan)
8. 1992)
Abstract The structure of [(E,E~-3,4-bis~2,4,6-tri-t-butyiphenylphosphinid~ne~-l,2-bis(trimethylsilyl~yclobutene~tetracarb~nylmo~ybdenum~0~ has been analyzed by X-ray crystallography. The structure of the free ligand, diphosphinidenecyclobutene, has also been analyzed and compared with that of the metal carbonyl complex.
Bidentate diphosphane ligands with sp”-type hybridized phosphorus atoms such as 1,2-bis(diphenylphosphino)ethane (dppe) have been widely used in organometallit chemistry as well as in organic synthesis 111. In contrast, bidentate phosphaalkene ligands containing sp2-type hybridized phosphorus atoms are rarely used because of their instability at a low-coordinated phosphorus atom. However, our recent strategy of steric protection using bulhy substituents has permitted us to isolate those unusual compounds as stable species [2]. By introducing an extremely bulky 2,4,6-tri-t-butylphenyl group (Ar group) into a molecule, we have been successful in preparing various types of compounds carrying phosphorus atoms in low coordination states such as diphosphenes [3], phosphaalkenes [4], and phosphacumulenes [5]. Some sterically protected 1,4-diphospha-1,IVbutadienes had been prepared by Appel et al. [6-81 and more recently a 2,2-biphosphinine had been synthesized by Mathey et al. [9] as a phosphorus analogue of bipyridine. Recently, Mark1 et al. [ 101 and we [ll] have independently reported the preparations of 3,4-bis(2,4,6-tri-t-butylphenylphosphinidene~-1,2-bis(trimethylsilyl)cyclobutenes (4 and 5) cia sigmatropic rearrangement from 1,6-diphospha-1,2,4,5hexatetraene (3) and/or diethynyldiphosphane (21, which was prepared from trimethylsilylethynylphosphane (1). The diphosphinidenecyclobutenes 4 and 5 might
Correspondence to: Dr. M. Yoshifuji, Department of Chemistry, Faculty of Science. Tohoku Aoba, Sendai 980, Japan; or Dr. K. Hirotsu, Department of Chemistry, Faculty of Science, University, Sumiyoshi, Osaka 558, Japan. 0022-328X/92/$05.00
@ 1992 - Elsevier
Sequoia
S.A. All rights reserved
University, Osaka City
c37
Table
1
Selected 4”
bond lengths
(A) and angles (“1, dihedral
Bond lengths Cl-C2 1.498(g) cz-c3 1.49203) c3-c4 1.400(9)
Cl-C4 PI-Cl P2-c2
Bond angles C2-Cl-C4 Cl-CZ-C3 C2-C3-C4 c3-C4-Cl
PI-Cl-C2 PI-Cl-C4 P2-C2-Cl P2-c2-c3
88.0(4) 88.0(4) 91.W) 91.7(5)
Dihedral angles c4-Cl-Cz-c3 5.4(5) Cl-c2-c3-c4 -5.7(S) CZ-C3-C4-Cl 5.8(5) C3-C4-Cl-C2 -5.7(5)
U Numbers
Table
in parentheses
1.493(8) l&78(6) 1.676(S)
P2 ’ . C32 P2. . * C38 Cl ‘.’ c22
are estimated
Pl-C5 P2-C23
121.8(J) 150x2(51 122.%4) 147.7w
Pl-Cl-c2-P2 Pl-Cl-C4-Si2 P2-CZ-C3-Sil
~ntram5~ecu~arshort contacts Pl . Cl3 3.1X1) Pl . ‘ . C21 3.074(8) P2. I . C30 3.370(8)
angles Y), and intramolecular
15.5(8) -8(l) -29(l)
3.208(8) 3.234W 3.47(l)
standard
short contacts
t/% for
1.841(6) 1.852(h)
Cl-PI-C5 CZ-PZ-C23
110.7(3) 108.0(3)
Si 1-C3-C4-Si2 Cl-Pl-C5-C6 C2-PZ-C23-C24
c5 . c44 C40 I . C42 C43 . . C46
15(l) -96.3W 103.2f.5)
3.46(l) 3.68( 1) 3.57(l)
deviations.
2
Selected 6U
bond lengths
L&J and angles (“1, dihedral
Bond lengths Cl-C2 1.483&j C2-C3 1.466(6) c3-C4 1.38X6) Cl-C4 1.469(h)
PI-Cl P2-C2 Pl-C5 P2-C23
Bond angles C2-Cl -C4 87.9(3) Cl-C2-C3 88.0(3f C2-C3-C4 92.0(4) C3-C4-Cl 91.8(3) PI-Cl-C2 120.7f3)
PI-Cl-C4 P2-c2-Cl P2-C2-C3 Cl-PI-G C2-P2-C23
Dihedral angles C4-Cl-C2-C3 3.3(3) Cl-C2-C3-C4 - 3.5(3) C2-C3-C4-Cl 3.6(3) C3-C4-Cl-C2 - 3.5(3)
PI-Cl-c2-P2 Pl-Cl-C4-Si2 P2-C%C3-Sil Sil -C3-C4-Si2
Intramolecufar short contacts Pl Cl3 3.286(8) Pl ‘. Cl4 3.293(7) Pl ’ . C22 3.276(6) P2 . . . C30 3.244(6) P2 . ’ C40 3.220(6)
Cl . . . Cl4 c2 ’ . C40 Cl0 . c44 c13,. I C48 c21 . . C47
Q Numbers
in parentheses
are estimated
angles V’), and intramolecular
Pl-MO P2-MO
1.680(4) 1.686(4) 1.836(4) 1.825(4)
151.2(3) 119.9(3) 151.9t3) 109.7(2) 108.7(2)
lO.l(Sf -19(l) -9(l) 11.8(8)
3.248(8) 3.348(6) 3.41903) 3.36( 1) 3.487(g)
standard
deviations.
short contacts
2.539(l) 2.526(l)
Pl-MO-P2 MO-PI-Cl MO-P2-C2
Cl-PI-CS-C6 C2-P2-C23-C24
78.10(4) 109.9(l) 110.7(I)
- 77.%4) 95.2(4)
c21 . cso 3.434(9) C3 I . .. C48 3.447(8) C43.. C46 3.52(l)
(A) for
C48
Pi
c49
c39
was added at that temperature to give 1,2-bis(2,4,6-tri-t-butylphenyl)-l,Zbis(trimethylsilylethynyl)diphosphane (2). The diphosphane 2 was unstable towards heat and gradually isomerized, even at room temperature, to a phosphaallenyl compound, 3,4-bis(trimethylsilyl)-1,6-bis(2,4,6-tri-t-butylphenyl)-1,6-diphospha-l,2,4,5hexatetraene (3). This phosphaallenyl compound 3 was further converted, but very slowly, at room temperature to the (E,E)_3,4-diphosphinidenecyclobutene 4. Yellow crystals. M.p.: 160-162°C. ‘H NMR (200 MHz, CDCl,, 25°C): S = 7.39 (4 H, S, arom.), 1.56 (36 H, s, o-‘Bu), 1.31 (18 H, s, p-‘Bu), and -0.33 (18 H, s, SiMe,). 31P{1H}NMR (81 MHz, CDCl,, 25°C): S = 162.9. ‘3C11H} NMR (50 MHz, CDCl,, 25°C): 6 = 183.9 (dd, J(PC) = 18.3 and 14.1 Hz; P = C), 176.2 (pseudo t, J(PC) = 4.6 Hz; CSiMe,), 154.8 (s, o-arom.), 149.5 (s, p-arom.), 136.8 (pseudo t, J(PC) = 29.0 Hz, r&o-arom.), 121.9 (s, m-arom.), 38.3 (s, oXMe,), 35.0 (s, p-CMe,), 33.4 (pseudo t, J(PC) = 3.7 Hz, o-CMe,), 31.3 (s, p-CMe,), and 0.4 (s, SiMe,). UV (hexane): A = 255 (log E 4.37), 298 (4.39), 314 (4.41), and 368 nm (sh, 3.69). IR (KBr): 1591 and 1477 cm-r. MS m/z (rel. intensity): 746 (W, 100) 689 (W- ‘Bu, 73), and 373 (ArPCzTms, 36). The yield of 4 based on 1 was 44% together with 3 (35% yield), after 30 min refluxing in toluene without the isolation process of 2. Because of facile photoisomerization by sunlight between 4 and 5, the whole procedure treating 4 was carried out in the dark [20 * 1.
s
ArP( H)CI
‘BuLi
ArP(H)C=C-Tms
-
(1) ArP(Li)CsC-Tms
BrCH2CH2B,’
ArP-CrC-Tms
d
1
-
ArP-C=C-Tms (2) Ar
ArP=C=C-Tms
\
d d
ArP=C=C-Tms
c-c C_[
/
/
Tms
P h”,, Ar-P
“h \
c-c
/
(4)
7 methods A-C,
~OC~,Mo
J
\
C-b 4
j
c-c
2
Tms
/
z
Ar = 2,4,6-‘Bu,C,H,; Tms = Me,Si Method A: Mo(CO),, A; method B:P (thf)Mo(CO),; hepta-2,5-diene)Mo(CO),
/
\
Tms
Tms
\
(6)
Tms method
Scheme 1
* Reference
/
&-& \
(4)
Tms
5
Tms
Tms
c-c
/
C-k
\
(3) J
\
number with asterisk indicates
a note in the list of references.
C: (bicyclo[2.2.11
c40
Preparation of [( E,E)-3,4-Bis(2,4,6-tri-t-butylphenylphosphinidene)-l,2-bis(trimethylsiiylkyclobutene]tetracarbonylmolybdenum (0) (6). The complex 6 was prepared according to the following three methods [12]. A solution of 4 (25.0 mg, 0.033 mmol) and 5.1 mol. equiv. of Mo(CO), (44.0 mg, 0.17 mmol) in dioxane (2.5 ml) was refluxed in the dark for 1 h (method A). Removal of the solvent under reduced pressure followed by flash column chromatography (SiO,/pentane) afforded 24.1 mg (76%) of 6. The reaction of 4 with excess (THF)Mo(CO), (5 mol equiv.) in THF at room temperature for 3 h (method B) also afforded the complex 6 in 75% yield. The reaction of 4 with 1.5 mol equiv. of (bicyclo[2.2.l]hepta-2,5-diene)tetracarbonylmolybdenum(O) in refluxing toluene for 20 h (method C) gave the same molybdenum(O) complex 6 in 44% yield. Crystal data and data collection for 4. The compound 4 was recrystallized from M =?47.23, monoclinic, space group P2,/n, benzene/acetonitrile. C,,H,,P,Si,, a = 9.543(l), b = 33.486(3), c = 15.218(2) A, p = 99396(l)“, U = 4789.6(9) A3, 2 = 4, D, = 1.037 g cme3, radiation: Cu-K, (A = 1.5418 A), p = 15.00 cm-‘, data collection: o-scan, 20 range: 2-120“, number of independent reflections: 5957, number of reflections used (I > 2a(Z)): 4075. Crystal data and data collection for 6. The complex 6 was recrystallized from A4 = 955.2& monoclinic, space group P2,/n, a = pentane. C,,H,,MoO,P,Si,, 16.116(3), b = 12.329(l), c = 28.208(7) A, p = 97.!9(3)“, U = 5552(2) A3, Z = 4, D, = 1.143 g cmV3, radiation: MO-K, (A = 0.7107 A), p = 3.64 cm-‘, data collection: w-scan, 20 range: l-50”, number of independent reflections: 9783, number of reflections used (I > 3&Z)): 6929. Both structures of 4 and 6 were solved using SHELX~~ [21]. All hydrogen atoms, except for those of p-t-butyl groups, could be located on difference Fourier syntheses. Full-matrix least-squares refinements with anisotropic temperature factors for non-hydrogen atoms and isotropic hydrogens converged to R = 0.075 and R, = 0.098 for 4 and R = 0.058 and R, = 0.059 for 6 [22]. Atomic coordinates, thermal parameters, and bond lengths and angles have been deposited at the Cambridge Crystallographic Data Centre. Acknowledgments. This work was supported in part by Grants-in-Aid for Scientific Research (Nos. 02403008, 02740251, and 02247104) from the Ministry of Education, Science and Culture, Japanese Government and the Asahi Glass Foundation. We thank the Research Centre for Protein Engineering, Institute for Protein Research at Osaka University for computer calculation of X-ray analysis. We also thank Tosoh Akzo Co. Ltd., Hodogaya Chemical Co., Ltd., and Shin-Etsu Chemical Co., Ltd., for chemicals. References and notes 1 E.C. Alyea and D.W. Meek (Eds.), Catalytic Aspects of Metal Phosphine Complexes, American Chemical Society, Washington DC, 1982. 2 M. Regitz and O.J. Scherer (Eds.), Multiple Bonds and Low Coordination in Phosphorus Chemistry, Georg Thieme Verlag, Stuttgart, 1990. 3 M. Yoshifuji, I. Shima, N. Inamoto, K. Hirotsu and T. Higuchi, J. Am. Chem. Sot., 103 (198114587 and 104 (1982) 6167. 4 M. Yoshifuji, K. Toyota and N. Inamoto, Tetrahedron Lett., 26 (1985) 1727. 5 M. Yoshifuji, K. Toyota, K. Shibayama and N. Inamoto, Tetrahedron Lett., 25 (19841 1809; M. Yoshifuji, K. Toyota and N. Inamoto, J. Chem. Sot., Chem. Commun., (1984) 689.
c41 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22
R. Appel, J. Hiinerbein and N. Siabalis, Angew. Chem., Int. Ed. Engl., 26 (1987) 779. R. Appel, B. Niemann, W. Schuhn and N. Siabalis, J. Organomet. Chem., 347 (1988) 299. R. Appel, V. Winkhaus and F. Knoch, Chem. Ber., 120 (1987) 243. P. Le Floch, D. Carmichael, L. Ricard and F. Mathey, J. Am. Chem. Sot., 113 (1991) 667. G. MIrkl, P. Kreitmeier, H. Ndth and K. Polborn, Angew. Chem., Int. Ed. Engl., 29 (1990) 927. M. Yoshifuji, K. Toyota, M. Murayama, H. Yoshimura, A. Okamoto, K. Hirotsu and S. Nagase, Chem. Lett., (19901 2195. K. Toyota, K. Tashiro and M. Yoshifuji, Chem. Lett., (1991) 2079. A part of this work was presented at the 62nd National Meeting of the Chemical Society of Japan, Sapporo, September 1991, Abstr. No. 2B215. C.K. Johnson, ORTEP-II, Oak Ridge National Laboratory Report, ORNL-TM-5138, Oak Ridge, TN, 1976. M. Yoshifuji, N. Inamoto, K. Hirotsu and T. Higuchi, I. Chem. Sot., Chem. Commun., (1985) 1109. M. Yoshifuji, S. Sasaki and N. Inamoto, Tetrahedron Lett., 30 (1989) 839. A.H. Cowley, J.E. Kilduff, N.C. Norman, M. Pakulski, J.L. Atwood and W.E. Hunter, J. Am. Chem. Sot., 105 (1983) 4845. G. Miirkl and U. Herold, Tetrahedron Lett., 29 (1988) 2935. G. Miirkl and P. Kreitmeier, Angew. Chem., Int. Ed. Engl., 27 (1988) 1360. The synthesis and X-ray structure of (E,Z)_S has been reported independently by us [ll] and by Mlrkl et al. [lo]. It should be noted that Miirkl et al. assigned a singlet peak (8(P) 164.911 in “P NMR to that for (E,ZJ-5 [lo]. However, as we have reported in the previous paper Ill], (E,Zl-5 was observed in AB pattern (8(P) 197.4 and 176.6, ‘J(PPl= 14.6 Hz), although the X-ray structures for (.E,ZJ-5 were both the same. It seems likely that the spectroscopic data reported by Mark1 et al. for “(E,Z)-5” correspond to those of our (E,E)-4 (S(P) 162.91, the structure of which was confirmed by the X-ray analysis as shown in this text. This discrepancy may be due to the facile E-Z photosiomerization [ll], which can take place during the recrystallization process for the X-ray analysis. All our recrystallization processes for (E,Zl-5, (E, El-4, and 6 were performed in the dark. G.M. Sheldrick, SHELX~~: Programs for the Automatic Solution of Crystal Structures, University of Gottingen, Germany, 1986. W.R. Busing, K.O. Martin and H.S. Levy, ORFLS, Oak Ridge National Laboratory Report, ORNL-TM-305, Oak Ridge, TN, 1965.
Journal of Org~no~zeta~lic Chemistry, 431 (1992) C3S-C41 Elsevier Sequoia S.A., Lausanne
JOM 22766PC Preliminary communication -
X-Ray structure analyses of diphosphinidenecyclobutene and its chelate type tetracarbonylmolybdenum(0) complex Kozo Toyota, Katsuya Tashiro, Masaaki Yoshifuji Department
of Chemistry, Faculty of Science, Tohoku Unic>ersity,Aoha, Sendai 980 (Japan)
Ikuko Miyahara, Atsuhiro Hayashi and Ken Hirotsu Department of Chemistry, Faculty of Science, Osuka Cily lJnil,ersity, (Received
February
Sumiyoshi, Osaka 558 (Japan)
8. 1992)
Abstract The structure of [(E,E~-3,4-bis~2,4,6-tri-t-butyiphenylphosphinid~ne~-l,2-bis(trimethylsilyl~yclobutene~tetracarb~nylmo~ybdenum~0~ has been analyzed by X-ray crystallography. The structure of the free ligand, diphosphinidenecyclobutene, has also been analyzed and compared with that of the metal carbonyl complex.
Bidentate diphosphane ligands with sp”-type hybridized phosphorus atoms such as 1,2-bis(diphenylphosphino)ethane (dppe) have been widely used in organometallit chemistry as well as in organic synthesis 111. In contrast, bidentate phosphaalkene ligands containing sp2-type hybridized phosphorus atoms are rarely used because of their instability at a low-coordinated phosphorus atom. However, our recent strategy of steric protection using bulhy substituents has permitted us to isolate those unusual compounds as stable species [2]. By introducing an extremely bulky 2,4,6-tri-t-butylphenyl group (Ar group) into a molecule, we have been successful in preparing various types of compounds carrying phosphorus atoms in low coordination states such as diphosphenes [3], phosphaalkenes [4], and phosphacumulenes [5]. Some sterically protected 1,4-diphospha-1,IVbutadienes had been prepared by Appel et al. [6-81 and more recently a 2,2-biphosphinine had been synthesized by Mathey et al. [9] as a phosphorus analogue of bipyridine. Recently, Mark1 et al. [ 101 and we [ll] have independently reported the preparations of 3,4-bis(2,4,6-tri-t-butylphenylphosphinidene~-1,2-bis(trimethylsilyl)cyclobutenes (4 and 5) cia sigmatropic rearrangement from 1,6-diphospha-1,2,4,5hexatetraene (3) and/or diethynyldiphosphane (21, which was prepared from trimethylsilylethynylphosphane (1). The diphosphinidenecyclobutenes 4 and 5 might
Correspondence to: Dr. M. Yoshifuji, Department of Chemistry, Faculty of Science. Tohoku Aoba, Sendai 980, Japan; or Dr. K. Hirotsu, Department of Chemistry, Faculty of Science, University, Sumiyoshi, Osaka 558, Japan. 0022-328X/92/$05.00
@ 1992 - Elsevier
Sequoia
S.A. All rights reserved
University, Osaka City
c37
Table
1
Selected 4”
bond lengths
(A) and angles (“1, dihedral
Bond lengths Cl-C2 1.498(g) cz-c3 1.49203) c3-c4 1.400(9)
Cl-C4 PI-Cl P2-c2
Bond angles C2-Cl-C4 Cl-CZ-C3 C2-C3-C4 c3-C4-Cl
PI-Cl-C2 PI-Cl-C4 P2-C2-Cl P2-c2-c3
88.0(4) 88.0(4) 91.W) 91.7(5)
Dihedral angles c4-Cl-Cz-c3 5.4(5) Cl-c2-c3-c4 -5.7(S) CZ-C3-C4-Cl 5.8(5) C3-C4-Cl-C2 -5.7(5)
U Numbers
Table
in parentheses
1.493(8) l&78(6) 1.676(S)
P2 ’ . C32 P2. . * C38 Cl ‘.’ c22
are estimated
Pl-C5 P2-C23
121.8(J) 150x2(51 122.%4) 147.7w
Pl-Cl-c2-P2 Pl-Cl-C4-Si2 P2-CZ-C3-Sil
~ntram5~ecu~arshort contacts Pl . Cl3 3.1X1) Pl . ‘ . C21 3.074(8) P2. I . C30 3.370(8)
angles Y), and intramolecular
15.5(8) -8(l) -29(l)
3.208(8) 3.234W 3.47(l)
standard
short contacts
t/% for
1.841(6) 1.852(h)
Cl-PI-C5 CZ-PZ-C23
110.7(3) 108.0(3)
Si 1-C3-C4-Si2 Cl-Pl-C5-C6 C2-PZ-C23-C24
c5 . c44 C40 I . C42 C43 . . C46
15(l) -96.3W 103.2f.5)
3.46(l) 3.68( 1) 3.57(l)
deviations.
2
Selected 6U
bond lengths
L&J and angles (“1, dihedral
Bond lengths Cl-C2 1.483&j C2-C3 1.466(6) c3-C4 1.38X6) Cl-C4 1.469(h)
PI-Cl P2-C2 Pl-C5 P2-C23
Bond angles C2-Cl -C4 87.9(3) Cl-C2-C3 88.0(3f C2-C3-C4 92.0(4) C3-C4-Cl 91.8(3) PI-Cl-C2 120.7f3)
PI-Cl-C4 P2-c2-Cl P2-C2-C3 Cl-PI-G C2-P2-C23
Dihedral angles C4-Cl-C2-C3 3.3(3) Cl-C2-C3-C4 - 3.5(3) C2-C3-C4-Cl 3.6(3) C3-C4-Cl-C2 - 3.5(3)
PI-Cl-c2-P2 Pl-Cl-C4-Si2 P2-C%C3-Sil Sil -C3-C4-Si2
Intramolecufar short contacts Pl Cl3 3.286(8) Pl ‘. Cl4 3.293(7) Pl ’ . C22 3.276(6) P2 . . . C30 3.244(6) P2 . ’ C40 3.220(6)
Cl . . . Cl4 c2 ’ . C40 Cl0 . c44 c13,. I C48 c21 . . C47
Q Numbers
in parentheses
are estimated
angles V’), and intramolecular
Pl-MO P2-MO
1.680(4) 1.686(4) 1.836(4) 1.825(4)
151.2(3) 119.9(3) 151.9t3) 109.7(2) 108.7(2)
lO.l(Sf -19(l) -9(l) 11.8(8)
3.248(8) 3.348(6) 3.41903) 3.36( 1) 3.487(g)
standard
deviations.
short contacts
2.539(l) 2.526(l)
Pl-MO-P2 MO-PI-Cl MO-P2-C2
Cl-PI-CS-C6 C2-P2-C23-C24
78.10(4) 109.9(l) 110.7(I)
- 77.%4) 95.2(4)
c21 . cso 3.434(9) C3 I . .. C48 3.447(8) C43.. C46 3.52(l)
(A) for
C48
Pi
c49
c39
was added at that temperature to give 1,2-bis(2,4,6-tri-t-butylphenyl)-l,Zbis(trimethylsilylethynyl)diphosphane (2). The diphosphane 2 was unstable towards heat and gradually isomerized, even at room temperature, to a phosphaallenyl compound, 3,4-bis(trimethylsilyl)-1,6-bis(2,4,6-tri-t-butylphenyl)-1,6-diphospha-l,2,4,5hexatetraene (3). This phosphaallenyl compound 3 was further converted, but very slowly, at room temperature to the (E,E)_3,4-diphosphinidenecyclobutene 4. Yellow crystals. M.p.: 160-162°C. ‘H NMR (200 MHz, CDCl,, 25°C): S = 7.39 (4 H, S, arom.), 1.56 (36 H, s, o-‘Bu), 1.31 (18 H, s, p-‘Bu), and -0.33 (18 H, s, SiMe,). 31P{1H}NMR (81 MHz, CDCl,, 25°C): S = 162.9. ‘3C11H} NMR (50 MHz, CDCl,, 25°C): 6 = 183.9 (dd, J(PC) = 18.3 and 14.1 Hz; P = C), 176.2 (pseudo t, J(PC) = 4.6 Hz; CSiMe,), 154.8 (s, o-arom.), 149.5 (s, p-arom.), 136.8 (pseudo t, J(PC) = 29.0 Hz, r&o-arom.), 121.9 (s, m-arom.), 38.3 (s, oXMe,), 35.0 (s, p-CMe,), 33.4 (pseudo t, J(PC) = 3.7 Hz, o-CMe,), 31.3 (s, p-CMe,), and 0.4 (s, SiMe,). UV (hexane): A = 255 (log E 4.37), 298 (4.39), 314 (4.41), and 368 nm (sh, 3.69). IR (KBr): 1591 and 1477 cm-r. MS m/z (rel. intensity): 746 (W, 100) 689 (W- ‘Bu, 73), and 373 (ArPCzTms, 36). The yield of 4 based on 1 was 44% together with 3 (35% yield), after 30 min refluxing in toluene without the isolation process of 2. Because of facile photoisomerization by sunlight between 4 and 5, the whole procedure treating 4 was carried out in the dark [20 * 1.
s
ArP( H)CI
‘BuLi
ArP(H)C=C-Tms
-
(1) ArP(Li)CsC-Tms
BrCH2CH2B,’
ArP-CrC-Tms
d
1
-
ArP-C=C-Tms (2) Ar
ArP=C=C-Tms
\
d d
ArP=C=C-Tms
c-c C_[
/
/
Tms
P h”,, Ar-P
“h \
c-c
/
(4)
7 methods A-C,
~OC~,Mo
J
\
C-b 4
j
c-c
2
Tms
/
z
Ar = 2,4,6-‘Bu,C,H,; Tms = Me,Si Method A: Mo(CO),, A; method B:P (thf)Mo(CO),; hepta-2,5-diene)Mo(CO),
/
\
Tms
Tms
\
(6)
Tms method
Scheme 1
* Reference
/
&-& \
(4)
Tms
5
Tms
Tms
c-c
/
C-k
\
(3) J
\
number with asterisk indicates
a note in the list of references.
C: (bicyclo[2.2.11
c40
Preparation of [( E,E)-3,4-Bis(2,4,6-tri-t-butylphenylphosphinidene)-l,2-bis(trimethylsiiylkyclobutene]tetracarbonylmolybdenum (0) (6). The complex 6 was prepared according to the following three methods [12]. A solution of 4 (25.0 mg, 0.033 mmol) and 5.1 mol. equiv. of Mo(CO), (44.0 mg, 0.17 mmol) in dioxane (2.5 ml) was refluxed in the dark for 1 h (method A). Removal of the solvent under reduced pressure followed by flash column chromatography (SiO,/pentane) afforded 24.1 mg (76%) of 6. The reaction of 4 with excess (THF)Mo(CO), (5 mol equiv.) in THF at room temperature for 3 h (method B) also afforded the complex 6 in 75% yield. The reaction of 4 with 1.5 mol equiv. of (bicyclo[2.2.l]hepta-2,5-diene)tetracarbonylmolybdenum(O) in refluxing toluene for 20 h (method C) gave the same molybdenum(O) complex 6 in 44% yield. Crystal data and data collection for 4. The compound 4 was recrystallized from M =?47.23, monoclinic, space group P2,/n, benzene/acetonitrile. C,,H,,P,Si,, a = 9.543(l), b = 33.486(3), c = 15.218(2) A, p = 99396(l)“, U = 4789.6(9) A3, 2 = 4, D, = 1.037 g cme3, radiation: Cu-K, (A = 1.5418 A), p = 15.00 cm-‘, data collection: o-scan, 20 range: 2-120“, number of independent reflections: 5957, number of reflections used (I > 2a(Z)): 4075. Crystal data and data collection for 6. The complex 6 was recrystallized from A4 = 955.2& monoclinic, space group P2,/n, a = pentane. C,,H,,MoO,P,Si,, 16.116(3), b = 12.329(l), c = 28.208(7) A, p = 97.!9(3)“, U = 5552(2) A3, Z = 4, D, = 1.143 g cmV3, radiation: MO-K, (A = 0.7107 A), p = 3.64 cm-‘, data collection: w-scan, 20 range: l-50”, number of independent reflections: 9783, number of reflections used (I > 3&Z)): 6929. Both structures of 4 and 6 were solved using SHELX~~ [21]. All hydrogen atoms, except for those of p-t-butyl groups, could be located on difference Fourier syntheses. Full-matrix least-squares refinements with anisotropic temperature factors for non-hydrogen atoms and isotropic hydrogens converged to R = 0.075 and R, = 0.098 for 4 and R = 0.058 and R, = 0.059 for 6 [22]. Atomic coordinates, thermal parameters, and bond lengths and angles have been deposited at the Cambridge Crystallographic Data Centre. Acknowledgments. This work was supported in part by Grants-in-Aid for Scientific Research (Nos. 02403008, 02740251, and 02247104) from the Ministry of Education, Science and Culture, Japanese Government and the Asahi Glass Foundation. We thank the Research Centre for Protein Engineering, Institute for Protein Research at Osaka University for computer calculation of X-ray analysis. We also thank Tosoh Akzo Co. Ltd., Hodogaya Chemical Co., Ltd., and Shin-Etsu Chemical Co., Ltd., for chemicals. References and notes 1 E.C. Alyea and D.W. Meek (Eds.), Catalytic Aspects of Metal Phosphine Complexes, American Chemical Society, Washington DC, 1982. 2 M. Regitz and O.J. Scherer (Eds.), Multiple Bonds and Low Coordination in Phosphorus Chemistry, Georg Thieme Verlag, Stuttgart, 1990. 3 M. Yoshifuji, I. Shima, N. Inamoto, K. Hirotsu and T. Higuchi, J. Am. Chem. Sot., 103 (198114587 and 104 (1982) 6167. 4 M. Yoshifuji, K. Toyota and N. Inamoto, Tetrahedron Lett., 26 (1985) 1727. 5 M. Yoshifuji, K. Toyota, K. Shibayama and N. Inamoto, Tetrahedron Lett., 25 (19841 1809; M. Yoshifuji, K. Toyota and N. Inamoto, J. Chem. Sot., Chem. Commun., (1984) 689.
c41 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22
R. Appel, J. Hiinerbein and N. Siabalis, Angew. Chem., Int. Ed. Engl., 26 (1987) 779. R. Appel, B. Niemann, W. Schuhn and N. Siabalis, J. Organomet. Chem., 347 (1988) 299. R. Appel, V. Winkhaus and F. Knoch, Chem. Ber., 120 (1987) 243. P. Le Floch, D. Carmichael, L. Ricard and F. Mathey, J. Am. Chem. Sot., 113 (1991) 667. G. MIrkl, P. Kreitmeier, H. Ndth and K. Polborn, Angew. Chem., Int. Ed. Engl., 29 (1990) 927. M. Yoshifuji, K. Toyota, M. Murayama, H. Yoshimura, A. Okamoto, K. Hirotsu and S. Nagase, Chem. Lett., (19901 2195. K. Toyota, K. Tashiro and M. Yoshifuji, Chem. Lett., (1991) 2079. A part of this work was presented at the 62nd National Meeting of the Chemical Society of Japan, Sapporo, September 1991, Abstr. No. 2B215. C.K. Johnson, ORTEP-II, Oak Ridge National Laboratory Report, ORNL-TM-5138, Oak Ridge, TN, 1976. M. Yoshifuji, N. Inamoto, K. Hirotsu and T. Higuchi, I. Chem. Sot., Chem. Commun., (1985) 1109. M. Yoshifuji, S. Sasaki and N. Inamoto, Tetrahedron Lett., 30 (1989) 839. A.H. Cowley, J.E. Kilduff, N.C. Norman, M. Pakulski, J.L. Atwood and W.E. Hunter, J. Am. Chem. Sot., 105 (1983) 4845. G. Miirkl and U. Herold, Tetrahedron Lett., 29 (1988) 2935. G. Miirkl and P. Kreitmeier, Angew. Chem., Int. Ed. Engl., 27 (1988) 1360. The synthesis and X-ray structure of (E,Z)_S has been reported independently by us [ll] and by Mlrkl et al. [lo]. It should be noted that Miirkl et al. assigned a singlet peak (8(P) 164.911 in “P NMR to that for (E,ZJ-5 [lo]. However, as we have reported in the previous paper Ill], (E,Zl-5 was observed in AB pattern (8(P) 197.4 and 176.6, ‘J(PPl= 14.6 Hz), although the X-ray structures for (.E,ZJ-5 were both the same. It seems likely that the spectroscopic data reported by Mark1 et al. for “(E,Z)-5” correspond to those of our (E,E)-4 (S(P) 162.91, the structure of which was confirmed by the X-ray analysis as shown in this text. This discrepancy may be due to the facile E-Z photosiomerization [ll], which can take place during the recrystallization process for the X-ray analysis. All our recrystallization processes for (E,Zl-5, (E, El-4, and 6 were performed in the dark. G.M. Sheldrick, SHELX~~: Programs for the Automatic Solution of Crystal Structures, University of Gottingen, Germany, 1986. W.R. Busing, K.O. Martin and H.S. Levy, ORFLS, Oak Ridge National Laboratory Report, ORNL-TM-305, Oak Ridge, TN, 1965.