Theoretical study of the mechanism of Pd(II)-catalyzed nucleophilic addition initiated by aminopalladation

Computational and Theoretical Chemistry 1170 (2019) 112638

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Theoretical study of the mechanism of Pd(II)-catalyzed nucleophilic addition initiated by aminopalladation ⁎

Wen-Mei Weia, Feng-Qi Donga, Ren-Hui Zhengb, , Xue Yanga, Wei-Jun Fanga, Yi-De Qina,

T ⁎

a

School of Basic Medical Science, Anhui Medical University, Hefei, Anhui 230032, PR China Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, PR China

b

A R T I C LE I N FO

A B S T R A C T

Keywords: Pd(II)-catalyzed Aminopalladation Potential energy surface Reaction mechanism Theoretical study

Palladium(II) complexes are important in organometallic chemistry because they are easily stored and handled due to their electrophilicity and solubility in most common organic solvents. Here, we study the potential energy surface of the reaction of Pd(II)-catalyzed nucleophilic addition initiated by aminopalladation using density functional theory calculations and elucidate its mechanism. The results show that the reaction paths suggested in He et al. [32] are unlikely to occur due to the high energy of their reaction barriers. We also propose a new reaction path that can produce the corresponding products.

1. Introduction Transition-metal-catalyzed nucleophilic addition of organometallic reagents to polar unsaturated substrates is one of the most powerful and important bond-forming strategies, and this approach has a wide variety of applications ranging from the synthesis of complex natural products to industrial processes [1]. In the pantheon of catalysts for organic synthesis, palladium (Pd) occupies a pre-eminent spot among transition metals. Palladium-catalyzed oxidative addition/reductive elimination reactions offer significantly shorter routes to the desired products and minimize side-products and waste, thus serving as a powerful method for the construction of heterocycles [2]. Palladium has been widely used for its effect on different types of reactions under relatively mild conditions, including numerous carbon-carbon bond forming reactions [2]. Because most palladium-based processes are stereo- and regioselective with excellent yields, various aspects of organopalladium chemistry have been reported in many books [3–6] and review papers [7–16]. Palladium complexes exist in three oxidation states, Pd(0), Pd(II), and Pd(IV), among which Palladium(II) complexes are particularly important in organopalladium chemistry because they are easily stored and handled due to their electrophilicity and solubility in most common organic solvents [2]. Many studies have been carried out on the Pd(II)-catalyzed reaction. For example, Shen et al. developed a method for cationic Pd(II)-catalyzed reductive cyclization of alkynetethered ketones or aldehydes using ethanol as a hydrogen source under mild conditions [17]. The same group also developed a highly efficient

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and redox-free Pd(II)-catalyzed tandem cyclization reaction initiated by intramolecular aminopalladation of alkynes followed by nucleophilic addition to nitriles [18]. Using Pd(CH3CN)2Cl2 as catalyst, Chen et al. developed the first catalytic trifluoromethoxylation of unactivated alkenes [19]. The Pd(II)-catalyzed dehydroboration of boron enolates generated from ketones and 9-iodo-9-borabicyclo[3.3.1]nonane was achieved by Sakamoto et al., providing a synthetically versatile protocol from ketones to alpha, beta- unsaturated ketones [20]. Naveen et al. reported Pd(II)-catalyzed, bidentate directing group-aided, chemoselective acetoxylation/substitution of remote epsilon-C(sp2)-H bonds that could be applied to heteroaryl-aryl-based biaryl systems [21]. An efficient Pd(II)-catalyzed synthesis of benzyl benzoates via direct functionalization of benzyl C(sp3)-H bonds was developed by Duanmu et al. [22], while Aebly et al. developed an enantioselective Pd (II)-catalyzed intramolecular oxidative amination reaction utilizing the commercially available chiral X-type ligand (1S)-(+)-camphorsulfonic acid [23]. Zhou et al. reported Pd(II)-catalyzed direct C(sp3)-H germylation of α–AA derivatives with the assistance of a bidentate auxiliary for the efficient synthesis of β-germyl-α-amino amides [24]. Pd (II)-catalyzed enantioselective C(sp3)-H cross-coupling of free carboxylic acids with organoborons has been realized by Hu et al. using either mono-protected amino acid (MPAA) ligands or mono-protected aminoethyl amine (MPAAM) ligands [25]. Pathare et al. have synthesized quinazoline-3-oxides via a Pd(II)-catalyzed azide-isocyanide coupling/cyclocondensation reaction [26]. Tetrahydroisoquinoline, which represents a motif that is ubiquitous

Corresponding authors. E-mail addresses: [email protected] (R.-H. Zheng), [email protected] (Y.-D. Qin).

https://doi.org/10.1016/j.comptc.2019.112638 Received 6 September 2019; Received in revised form 26 October 2019; Accepted 29 October 2019 Available online 31 October 2019 2210-271X/ © 2019 Elsevier B.V. All rights reserved.

Computational and Theoretical Chemistry 1170 (2019) 112638

W.-M. Wei, et al.

on the potential energy surface are listed in the Supporting Information. In the geometry of TS1, the bond-forming C7⋯C35 and Pd34⋯O37 distances are shortened to 1.900 and 1.893 Å, respectively, while the breaking C7ePd34 bond is lengthened to 2.413 Å. Subsequently, a proton is added to IM2 to form intermediate IM3, releasing Pd(II). Then, via transition state TS2 with a small barrier of 11.3 kcal/mol, IM3 can isomerize to IM4. This isomerization reaction rotates along the C7–H8 bond. Finally, IM4 dissociates to the products (Z)-2-benzyl-4benzylidene-1,2,3,4-tetrahydroisoquinoline (P1) and H2O via transition state TS3 with a barrier of 65.8 kcal/mol. In the structure of TS3, the bond-forming H8⋯O37 distance is reduced to 1.145 Å, while the breaking C7eH8 and C35eO37 bonds are elongated to 1.566 and 1.658 Å, respectively. In the calculation, all of the molecules and ions (H+ and Pd2+) were studied under the influence of the solvent effect. For example, the electronic and free energies of the proton in the ethanol solvent are −0.211051 and −0.225098 a.u., respectively, while they are 0.000000 and −0.014047 a.u. in vacuum. The solvation effect lowers the energy of the proton and make the proton more stable. The whole process of Path A is exothermic by 15.1 kcal/mol. However, the highest Gibbs free energy barrier of this path is 55.2 kcal/mol (imposed by TS1), indicating that it will be difficult for the path suggested in Ref. [32] to occur. All of the above computations were performed with the bare Pd (Pd2+). To study the influence of the bonding molecules or atoms on the reactions, we investigate PdCl2 instead of Pd2+ reacting with R1, and the total free energy of their products, IM1Cl2 and a proton, is 64.5 kcal/mol greater than that of R1 and PdCl2. The free energy is high; thus, it is difficult for the reaction to occur. However, the corresponding yield in experiment [32] can be 47%. Thus, Path A cannot occur and is not the mechanism of the reactions reported in Ref. [32].

in many natural alkaloids and biologically active compounds [27–29], has attracted particular interest in the fields of chemistry, biology, and drug development for the significant antimicrobial and antitumor activities and other biological properties [29–31]. Hu et al. investigated the reaction of N-benzyl-1-(2-vinylphenyl)methanamine with benzaldehyde in the presence of palladium catalyst and obtained a high yield of (Z)-2-benzyl-4-benzylidene-1,2,3,4-tetrahydroisoquinoline (47%) when the reaction was conducted at 110 °C in 2-PrOH with PdCl2/ Xantphos as the catalyst [32]. In this work, we study the potential energy surface of this reaction using density functional theory (DFT) calculations and seek to elucidate its mechanism. Previous research has shown that theoretical studies provide a better understanding of transition metal catalyzed organic synthetic transformations. Calculations can elucidate the reaction characteristics, such as the bonding and structure of the catalyst, the nature of the various transition states and the kinetic partitioning of the reductive elimination to form the desired product. [33]. Computational tools for mechanistic studies have indeed been the most important contributors in the verification of the mechanism of homogeneous catalysis derived from experimental studies [34–43]. To the best of our knowledge, no theoretical studies have been carried out on the detailed mechanism of the title reaction; thus, little is known about its mechanistic pathways, reactive intermediates and the transition states. In this paper, we explore the mechanism of the reaction theoretically. Our main purpose is to find the transition states in the rate-determining step of the reaction. 2. Computational details All calculations were performed using Gaussian 16 software [44]. Density functional theory (M08HX) [45] calculations were carried out to optimize the geometries of the stationary points and transition states on the potential energy surface. The ECP28MWB relativistic effective core potential basis set [46,47] was used for Pd atoms, and the standard 6-31G** basis set was adopted for the remaining elements (C, H, N, and O atoms). Harmonic vibrational frequencies (in cm−1), the corresponding zero-point vibrational energies (ZPVE, in kcal/mol) scaled by a factor of 0.96 [48], and entropy (S, in cal mol−1 K−1) were obtained at the same level of theory. The intrinsic reaction coordinate (IRC) approach was applied to confirm that the transition state does indeed connect the two relevant minima [49]. Reaction intermediates are denoted as IM and the transition state as TS in the following discussion. Relative Gibbs free energies (G, in kcal/mol) obtained at 393.15 K and 1 atm [32] were applied in the discussion below because the entropy effect may significantly change the potential energy surface. In the calculations described above, we apply an integral equation formalism variant (IEFPCM) approach using radii and nonelectrostatic terms for Truhlar’s SMD solvation method that can provide relatively accurate Gibbs free energy values [50], where the solvent is ethanol with a dielectric constant of 24.852 [32,44].

3.2. Path B Similar to the first step of Path A, R1 and Pd(II) first combine to form intermediate IM1H, but no proton is released. This reaction releases 114.9 kcal/mol (see Fig. 2). In fact, H+ will be given off in the final steps of Path B. Then, R2 is added to IM1H to form transition state TS1H with a barrier of 52.7 kcal/mol. Even though the barrier is high, the reaction can occur because the energy released in the previous step is much larger than the energy of the barrier. In the geometry of TS1H, the bond-forming C7⋯C35 and Pd34⋯O37 distances are shortened to 1.921 and 1.894 Å, respectively, while the breaking C7ePd34 bond is lengthened to 2.406 Å. Then, the C7ePd34 bond in TS1H is gradually broken, and C7eC35 and Pd34eO37 bonds are formed to produce IM2H. After that, a proton is added to IM2H to form intermediate IM3H while Pd(II) is released. Then, IM3H rearranges to IM4H via transition state TS2H with a low barrier of 11.4 kcal/mol. Similar to Path A, this isomerization process also rotates along the C7–H8 bond. Subsequently, IM4H decomposes to the products P1H and H2O through transition state TS3H with a barrier of 63.1 kcal/mol, where the barrier is also much smaller than the energy released in previous steps (see Fig. 2). In the structure of TS3H, the bond-forming H8⋯O37 distance is reduced to 1.122 Å, while the breaking C7eH8 and C35eO37 bonds are elongated to 1.610 and 1.574 Å, respectively. Finally, product P1 is obtained through the breaking NeH bond and releasing H+ in P1H. The P1H production from the initial reactants Pd(II) and R1 is exothermic by 156.1 kcal/mol, which is larger than the 141.0 kcal/mol required for the reaction from P1H to P1. Thus, production of P1 through Path B is feasible. The whole process of Path B is also exothermic by 15.1 kcal/mol, similar to that of Path A. Even though the highest Gibbs free energy barrier of this path is 52.7 kcal/mol (imposed by TS1H), the first step that generates IM1H is exothermic by −114.9 kcal/mol. Thus, this path will occur easily. Fig. 2 shows that the released energy of Path B is much larger than the energy of reaction barriers, indicating that Path B

3. Results and discussion Two paths are studied for the Pd(II)-catalyzed nucleophilic addition initiated by aminopalladation. The proposed mechanisms of this reaction are presented in Fig. 1(a) and (b), respectively. The potential energy diagram for this reaction is depicted in Fig. 2. 3.1. Path A Fig. 1(a) shows the proposed mechanism of Path A. In this path, Nbenzyl-1-(2-vinylphenyl)methanamine (R1) and Pd(II) first combine to form intermediate IM1, releasing a proton. Then, benzaldehyde (R2) reacts with IM1 via transition state TS1 with an energy barrier of 55.2 kcal/mol to form intermediate IM2. In this process, the C and O atoms in R2 are added to the C and Pd atoms in IM1 to form the CeC and OePd bonds, respectively. The Cartesian coordinates of the species 2

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(a)

(b) Fig. 1. Proposed mechanism of the Pd(II)-catalyzed nucleophilic addition initiated by aminopalladation. (a) Proton removal in the first step. (b) Proton removal in the last step.

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Fig. 2. Potential energy diagram for the Pd(II)-catalyzed nucleophilic addition initiated by aminopalladation. The more feasible route is shown by bold lines. The energy values (in kcal/mol) are the relative Gibbs free energies.

References

is a plausible mechanism of Pd(II)-catalyzed nucleophilic addition initiated by aminopalladation.

[1] L. Yang, H. Huang, Transition-metal-catalyzed direct addition of unactivated C-H bonds to polar unsaturated bonds, Chem. Rev. 115 (2015) 3468–3517. [2] G. Zeni, R.C. Larock, Synthesis of heterocycles via palladium-catalyzed oxidative addition, Chem. Rev. 106 (2006) 4644–4680. [3] E. Negishi, Handbook of Organopalladium Chemistry for Organic Synthesis vols. 1 and 2, Wiley and Sons, New York, 2002. [4] J.J. Li, G.W. Gribble, Palladium in Heterocyclic Chemistry, Pergamon, New York, 2000. [5] J. Tsuji, Palladium Reagents and Catalysts: Innovations in Organic Synthesis, Wiley and Sons, New York, 1995. [6] L.S. Liebeskind (Ed.), Advances in Metal-organic Chemistry, vol. V, JAI Press, London, 1994(Chapter 3). [7] R.E. Ziegert, J. Torang, K. Knepper, S. Brase, The recent impact of solid-phase synthesis on medicinally relevant benzoannelated oxygen heterocycles, J. Comb. Chem. 7 (2005) 147–169. [8] G. Zeni, R.C. Larock, Synthesis of heterocycles via palladium pi-olefin and pi-alkyne chemistry, Chem. Rev. 104 (2004) 2285–2309. [9] E. Negishi, L. Anastasia, Palladium-catalyzed alkynylation, Chem. Rev. 103 (2003) 1979–2017. [10] L.A. Agrofoglio, I. Gillaizeau, Y. Saito, Palladium-assisted routes to nucleosides, Chem. Rev. 103 (2003) 1875–1916. [11] J.A. Marshall, Synthesis and reactions of allylic, allenic, vinylic, and arylmetal reagents from halides and esters via transient organopalladium intermediates, Chem. Rev. 100 (2000) 3163–3185. [12] R. Zimmer, C.U. Dinesh, E. Nandanan, F.A. Khan, Palladium-catalyzed reactions of allenes, Chem. Rev. 100 (2000) 3067–3125. [13] I.P. Beletskaya, A.V. Cheprakov, The Heck reaction as a sharpening stone of palladium catalysis, Chem. Rev. 100 (2000) 3009–3066. [14] J. Tsuji, Recollections of organopalladium chemistry, Pure Appl. Chem. 71 (1999) 1539–1547. [15] L.S. Hegedus, Transition metals in organic synthesis. Highlights for the year 1995, Coord. Chem. Rev. 161 (1997) 129–255. [16] L.S. Hegedus, Transition metals in organic synthesis highlights for the year 1994, Coord. Chem. Rev. 147 (1996) 443–545. [17] K. Shen, X. Han, X. Lu, Cationic Pd(II)-catalyzed reductive cyclization of alkynetethered ketones or aldehydes using ethanol as hydrogen source, Org. Lett. 15 (2013) 1732–1735. [18] G. Xia, X. Han, X. Lu, Pd(II)-catalyzed one-step construction of cycloalkane-fused indoles and its application in formal synthesis of (+/-)-aspidospermidine, Org. Lett. 16 (2014) 2058–2061. [19] C. Chen, P. Chen, G. Liu, Palladium-catalyzed intramolecular aminotrifluoromethoxylation of alkenes, J. Am. Chem. Soc. 137 (2015) 15648–15651. [20] Y. Sakamoto, T. Amaya, T. Suzuki, T. Hirao, Palladium(II)-catalyzed

4. Conclusions Our calculations suggest that Path B is a feasible channel for the Pd (II)-catalyzed nucleophilic addition reaction initiated by aminopalladation, and the Gibbs free energy of the overall process is −15.1 kcal/ mol. Generally, the reaction in which R2 is added to IM1H to form a transition state TS1H with a barrier of 52.7 kcal/mol even at 393.15 K is unlikely to occur. However, the first step of Path B to produce IM1H is exothermic by 114.9 kcal/mol, which is much larger than the energy of the reaction barrier. When this large energy is transferred to the C-PdII bond and C···C bond, the transition state TS1H can be formed easily (see Fig. 2). Hence, the corresponding reaction producing IM2H through transition state TS1H can occur, and the reactions of Path B are feasible. In contrast, it will be difficult for Path A described in Ref. [32] to occur due to the high energy of its reaction barriers. Declaration of Competing Interest The authors declared that there is no conflict of interest. Acknowledgements This work was supported by Key Project of the Natural Science Research Fund for Colleges and Universities in Anhui Province (No. KJ2018A0173), National Natural Science Foundation of China (NNSF) (No. 91856122) and Science Research Fund of Anhui Medical University in 2018 (No. 2018xkj020). Appendix A. Supplementary material Supplementary data to this article can be found online at https:// doi.org/10.1016/j.comptc.2019.112638. 4

Computational and Theoretical Chemistry 1170 (2019) 112638

W.-M. Wei, et al.

[21]

[22]

[23]

[24]

[25]

[26]

[27]

[28] [29] [30] [31]

[32]

[33]

[34]

[35]

[36]

[37]

dehydroboration via generation of boron enolates, Chem. -Eur. J. 22 (2016) 18686–18689. V. Naveen, S.A. Rajkumar, B. Babu, Gopalakrishnan, Pd(II)-catalyzed bidentate directing group-aided chemoselective acetoxylation of remote ε-C(sp2)-H bonds in heteroaryl-aryl-based biaryl systems, J. Org. Chem. 81 (2016) 12197–12211. D. Duanmu, P.K. Leong, Q.B. Jiang, H. Yan, Pd(II)-catalyzed synthesis of benzyl benzoates via benzyl C(sp3)-H activation, Chin. J. Org. Chem. 37 (2017) 2669–2677. A.H. Aebly, T.J. Rainey, Pd(II)-catalyzed enantioselective intramolecular oxidative amination utilizing (+)-camphorsulfonic acid, Tetrahedron Lett. 58 (2017) 3795–3799. Z.X. Zhou, W.H. Rao, M.H. Zeng, Y.J. Liu, Facile synthesis of unnatural β-germyl-αamino amides via Pd(II)-catalyzed primary and secondary C(sp3)-H bond germylation, Chem. Commun. 54 (2018) 14136–14139. L. Hu, P.-X. Shen, Q. Shao, K. Hong, J.X. Qiao, J.-Q. Yu, PdII-catalyzed enantioselective C(sp3)-H activation/cross-coupling reactions of free carboxylic acids, Angew. Chem. Int. Ed. 58 (2019) 2134–2138. R.S. Pathare, A.K. Maurya, A. Kumari, V.K. Agnihotri, V.P. Verma, D.M. Sawant, Synthesis of quinazoline-3-oxides via a Pd(II) catalyzed azide-isocyanide coupling/ cyclocondensation reaction, Org. Biomol. Chem. 17 (2019) 363–368. L. Liu, B.C. Finzel, Fragment-based identification of an inducible binding site on cell surface receptor CD44 for the design of protein-carbohydrate interaction inhibitors, J. Med. Chem. 57 (2014) 2714–2725. K.W. Bentley, β-Phenylethylamines and the isoquinoline alkaloids, Nat. Prod. Rep. 23 (2006) 444–463. J.D. Scott, R.M. Williams, Chemistry and biology of the tetrahydroisoquinoline antitumor antibiotics, Chem. Rev. 102 (2002) 1669–1730. G.-L. Tang, M.-C. Tang, L.-Q. Song, Y. Zhang, Biosynthesis of tetrahydroisoquinoline antibiotics, Curr. Top. Med. Chem. 16 (2016) 1717–1726. V.H. Le, M. Inai, R.M. Williams, T. Kan, Ecteinascidins. A review of the chemistry, biology and clinical utility of potent tetrahydroisoquinoline antitumor antibiotics, Nat. Prod. Rep. 32 (2015) 328–347. Y. Hu, Y. Xie, Z. Shen, H. Huang, Palladium-catalyzed ring-forming aminoalkenylation of alkenes with aldehydes initiated by intramolecular aminopalladation, Angew. Chem. Int. Ed. 56 (2017) 2473–2477. (a) T.R. Cundari, J. Deng, Density functional theory study of palladium-catalyzed aryl-nitrogen and aryl-oxygen bond formation, J. Phys. Org. Chem. 18 (2005) 417–425; (b) R.A. Mata, Martin A. Suhm, Benchmarking quantum chemical methods: are we heading in the right direction? Angew. Chem. Int. Ed. 56 (2017) 11011–11018; (c) S. Grimme, P.R. Schreiner, Computational chemistry: The fate of current methods and future challenges, Angew. Chem. Int. Ed. 57 (2017) 4170–4176. J. Shi, B. Hu, P. Ren, S. Shang, X. Yang, D. Chen, Synthesis and reactivity of metal ligand cooperative bifunctional ruthenium hydride complexes: Active catalysts for β-Alkylation of secondary alcohols with primary alcohols, Organometallics 37 (2018) 2795–2806. J. Liu, L.R. Hu, L. Wang, H. Chen, L. Deng, An iron(II) ylide complex as a masked open-shell iron alkylidene species in its alkylidene-transfer reactions with alkenes, J. Am. Chem. Soc. 139 (2017) 3876–3888. J. Zhang, J.-Z. Xu, Z.-J. Zheng, Z. Xu, Y.-M. Cui, J. Cao, L.-W. Xu, Palladium-catalyzed desymmetrization of silacyclobutanes with alkynes to silicon-stereogenic silanes: a density functional theory study, Chem. Asian J. 11 (2016) 2867–2875. S. Ding, L.-J. Song, Y. Wang, X. Zhang, L.W. Chung, Y.-D. Wu, J. Sun, Highly regio-

[38]

[39]

[40]

[41]

[42] [43]

[44]

[45]

[46]

[47]

[48]

[49] [50]

5

and stereoselective hydrosilylation of internal thioalkynes under mild conditions, Angew. Chem. Int. Ed. 54 (2015) 5632–5635. J.L. Jiang, R. Ramozzi, K. Morokuma, Rh-III-catalyzed C(sp3)-H bond activation by an external base metalation/deprotonation mechanism: a theoretical study, Chem. Eur. J. 21 (2015) 11158–11164. T. Sperger, I.A. Sanhueza, I. Kalvet, F. Schoenebeck, Computational studies of synthetically relevant homogeneous organometallic catalysis involving Ni, Pd, Ir, and Rh: An overview of commonly employed DFT methods and mechanistic insights, Chem. Rev. 115 (2015) 9532–9586. Y. Yang, L.W. Chung, X. Zhang, K.N. Houk, Y.-D. Wu, Ligand-controlled reactivity, selectivity, and mechanism of cationic ruthenium-catalyzed hydrosilylations of alkynes, ketones, and nitriles: a theoretical study, J. Org. Chem. 79 (2014) 8856–8864. A.S.K. Tsang, I.A. Sanhueza, F. Schoenebeck, Combining experimental and computational studies to understand and predict reactivities of relevance to homogeneous catalysis, Chem. Eur. J. 20 (2014) 16432–16441. L.E. Rush, P.G. Pringle, J.N. Harvey, Computational kinetics of cobalt-catalyzed alkene hydroformylation, Angew. Chem. Int. Ed. 53 (2014) 8672–8676. L. Crawford, D.J. Cole-Hamilton, E. Drent, M. Buhl, Mechanism of alkyne alkoxycarbonylation at a Pd catalyst with P, N hemilabile ligands: a density functional study, Chem. Eur. J. 20 (2014) 13923–13926. M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman, G. Scalmani, V. Barone, G.A. Petersson, H. Nakatsuji, X. Li, M. Caricato, A.V. Marenich, J. Bloino, B.G. Janesko, R. Gomperts, B. Mennucci, H.P. Hratchian, J.V. Ortiz, A.F. Izmaylov, J.L. Sonnenberg, D. Williams-Young, F. Ding, F. Lipparini, F. Egidi, J. Goings, B. Peng, A. Petrone, T. Henderson, D. Ranasinghe, V.G. Zakrzewski, J. Gao, N. Rega, G. Zheng, W. Liang, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, K. Throssell, J.A. Montgomery Jr., J.E. Peralta, F. Ogliaro, M.J. Bearpark, J.J. Heyd, E.N. Brothers, K.N. Kudin, V.N. Staroverov, T.A. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A.P. Rendell, J.C. Burant, S.S. Iyengar, J. Tomasi, M. Cossi, J.M. Millam, M. Klene, C. Adamo, R. Cammi, J.W. Ochterski, R.L. Martin, K. Morokuma, O. Farkas, J.B. Foresman, D.J. Fox, GAUSSIAN 16, Revision A.03, Gaussian Inc., Wallingford, CT, 2016. Y. Zhao, D.G. Truhlar, Exploring the limit of accuracy of the global hybrid meta density functional for main-group thermochemistry, kinetics, and noncovalent interactions, J. Chem. Theory Comput. 4 (2008) 1849–1868. D. Andrae, U. Haeussermann, M. Dolg, H. Stoll, H. Preuss, Energy-adjusted ab initio pseudopotentials for the second and third row transition elements, Theor. Chim. Acta. 77 (1990) 123–141. J.M.L. Martin, A. Sundermann, Correlation consistent valence basis sets for use with the Stuttgart-Dresden-Bonn relativistic effective core potentials: the atoms Ga-Kr and In-Xe, J. Chem. Phys. 114 (2001) 3408–3420. M.L. Laury, M.J. Carlson, A.K. Wilson, Vibrational frequency scale factors for density functional theory and the polarization consistent basis sets, J. Comput. Chem. 33 (2012) 2380–2387. C. Gonzalez, H.B. Schlegel, An improved algorithm for reaction-path following, J. Chem. Phys. 90 (1989) 2154–2161. A.V. Marenich, C.J. Cramer, D.G. Truhlar, Universal solvation model based on solute electron density and on a continuum model of the solvent defined by the bulk dielectric constant and atomic surface tensions, J. Phys. Chem. B 113 (2009) 6378–6396.