Theoretical Investigation on Nickel-Catalyzed ... - ACS Publications

Article pubs.acs.org/Organometallics

Theoretical Investigation on Nickel-Catalyzed Hydrocarboxylation of Alkynes Employing Formic Acid Julong Jiang, Mingchen Fu, Cui Li, Rui Shang,*,† and Yao Fu* Hefei National Laboratory for Physical Sciences at the Microscale, iChEM, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei 230026, Anhui, People’s Republic of China S Supporting Information *

ABSTRACT: DFT calculations have been conducted to elucidate the mechanistic details of a novel Ni-catalyzed hydrocarboxylation reaction of alkynes, in which formic acid is atom-economically used through a catalytic CO recycling manner. On the basis of our theoretical investigations, the bisphosphine (dppbz, 1,2-bis(diphenylphosphino)benzene) ligated nickel monocarbonyl complex (dppbz)NiCO was located as the active catalytic species for this process, and such a carbonyl ligand is found to be critical for the final reductive elimination. Our studies also revealed the addition of H to alkynes proceeds via a proton transfer process directly from formic acid (i.e., outer-sphere pathway) rather than through a proposed hydrometalation process (i.e., direct hydride shift from Ni−H). The thermal decomposition of formic anhydrides was found to be vital to a successful reaction, and its barrier must be slightly higher than the energetic span of the Ni catalytic cycle. Fast release of CO can poison the Ni catalyst, so that the reaction would be shut down. Other intriguing experimental observations, such as ligand effect, regioselectivity, and extraordinary compatibility of C−X (X = halogen) bonds, are also discussed in this article.

■

INTRODUCTION Hydrocarboxylation, as an efficient strategy to functionalize unsaturated hydrocarbons, has attracted broad interest from both industry and academia.1 Works concerning hydrocarboxylation usually require the employment of CO2 and a reducing reagent under the catalysis of a transition metal.2 The transition metal varies from Rh and Pd to earth-abundant metals such as Fe and Ti.3 Meanwhile, formic acid, as a readily available chemical which can be obtained from the degradation of biomass,4 is proposed to be a good substrate due to a 100% atom economy for hydrocarboxylation. Normally, formic acid can be treated as a reductant (hydride donor) in a basic environment, and the hydrogenation of alkynes and alkenes using formic acid via extrusion of carbon dioxide has been reported.5 Han et al. reported that formic acid and alkynes do react with Pd catalyst to form a Pd complex bearing an alkenyl moiety and a formate ligand.6 However, the subsequent reductive elimination between these two moieties is actually blocked. It was also found that the presence of CO gas is necessary for hydrocarboxylation reactions, although the mechanistic details are still unclear.7 Nevertheless, pioneers working in this field turned their attention to the in situ generation of CO via a CO recycling strategy. Recently, the Zhou and Shi groups reported a novel Pd-catalyzed method to hydrocarboxylate unsaturated C−C bonds with CO generated in situ from formic acid (i.e., without external CO gas).8 © XXXX American Chemical Society

Inspired by these synthetic achievements, our group recently discovered that a low-cost and earth-abundant nickel catalyst is competent to catalyze the direct hydrocarboxylation of alkynes with remarkable chemo- and regioselectivity (see Scheme 1). Nickel-catalyzed hydrocarboxylation of alkynes with formic acid was also reported with an improved catalytic efficiency (TON up to 7700) by Zhou and co-workers.9 Scheme 1. Nickel-Catalyzed Hydrocarboxylation of Alkynes

Despite all the experimental achievements, many questions about the experimental details have yet to be clarified. First, although experimental evidence indicated that a carbonylation process is involved in the catalytic cycle, the origin of the sensitivity toward the amount of CO, as well as the exact effect of the carbonylation process in this reaction, is not clear. Received: April 22, 2017

A

DOI: 10.1021/acs.organomet.7b00310 Organometallics XXXX, XXX, XXX−XXX

Article

Organometallics

Scheme 2. Initially Proposed Hydride-Transfer Mechanism in Which the Reductive Elimination Step Is Proved to Be Blocked

Scheme 3. Energy Profile of the Outer-Sphere Protonation and the Following CO Insertion

■

COMPUTATIONAL METHODS All of the calculations were carried out at the DFT level of theory with the B3LYP hybrid functional,11 corrected with the empirical dispersion term (known as Grimme-D3),12 as implemented in the Gaussian09 package.13 The 6-311G(d,p) basis sets14 were employed for the C, H, O, and P atoms, and the SDD effective core potential (ECP) basis sets were applied to the Ni and I atoms.15 The polarization functions were added to both Ni and I atoms with coefficients of 3.130 and 0.289, respectively.16 The transition states were located by means of the QST3 method17 and the Berny algorithm.18 All of the reactant, intermediate, transition state, and product structures were fully optimized without any symmetric restrictions. The solvent effect was introduced through an IEF-PCM model19 with toluene as the solvent (ε = 2.3741) for both optimization and single-point calculations. Frequency calculations were carried out to ensure that the structure obtained is a real minimum or a transition state. Intrinsic reaction coordinate (IRC) calculations20 were conducted to confirm that the transition state is connected to the correct reactant and product. All of the enthalpies and Gibbs energies shown in this article were calculated at 1 atm and 298.15 K.

Second, a bidentate phosphine ligand is found to be necessary for this reaction. Other common monodentate ligands (e.g., PPh3) were proved to be useless, giving 0% yield of the desired product. Third, as highlighted in the newly developed strategies, toxic CO gas is replaced by formic acid, which can react with acid anhydrides and release CO in situ. However, we have found that only certain types of formic anhydride derivatives can promote this reaction. Regioselectivity for asymmetric alkynes is another feature of this hydrocarboxylation reaction. However, a hydride shift mechanism (i.e., transfer of H− from the Ni atom to the alkyne) cannot adequately explain the preference for Markovnikov product as observed experimentally. Finally, this Ni-catalyzed hydrocarboxylation shows an extraordinary compatibility of the C−X (X = halogen) bond existing in the substrate. No dehalogenation product via oxidative addition was detected, and the yield was still up to 50%. Such a result indeed goes against common sense.10 Overall, to answer the questions raised above, an extensive theoretical investigation was carried out to unveil the mechanistic details. Hopefully, it will be beneficial to those who work in the field of chemistry. B


Article

Organometallics

Starting from int6, since both formate and dppbz can switch their coordination pattern between monodentate and bidentate, a multistep barrierless isomerization will transform intermediate int6 into int6b, or the other way around. The latter is actually more stable than int6 by 58.8 kJ/mol and therefore acts a resting state prior to the final reductive elimination. As shown in Scheme 3, it was natural to consider a direct reductive elimination from the four-coordinate Ni(II) complex int6b, which affords product P2 and regenerates Ni(0) catalyst int0. However, our further calculations, including a PES scan, suggested that the direct elimination from int6b is not practical from a kinetic perspective (please refer to the Supporting Information for discussions on the origin). Meanwhile, this path is also thermodynamically unfavored. The enthalpy of the formed P6b is 61.8 kJ/mol higher than that of int6b. The further splitting of P2 from P6b (to allow the coordination of another alkyne) is even thermodynamically prohibited with an enthalpy change of +201.4 kJ/mol. Instead, carbon monoxide dissolved in the solvent, which was generated through the decarbonylation of formyl anhydrides, will participate in the reaction by breaking one Ni−O bond in int6 and directly ligating to the Ni atom. Such a process generates intermediate int7, which subsequently undergoes the final reductive elimination to afford P2 and regenerate the Ni(0) catalyst intI. Notably, P2 can undergo either a decarbonylation process or a hydrolysis pathway to afford the final desired product. According to the energetic-span model suggested by Kozuch et al.,25 the turnover-determining intermediate (i.e., TDI) in the Ni catalytic cycle is the van der Waals complex int6b_CO_vdW and the turnover-determining transition state (TDTS) is TS7. Since the TDI comes ahead of TDTS in the reaction pathway, the effective enthalpic barrier is therefore calculated as 92.3 kJ/mol. Given the relatively harsh reaction conditions (i.e., sealed tube, 100 °C, and 24 h), the calculated energetic span is reasonable. On the basis of our theoretical investigations, the existence of solvated CO is proved to be vital to a successful hydrocarboxylation. Moreover, one highlight in our synthetic protocol is the avoidance of using toxic CO gas, and the CO is believed to be formed in situ from the thermal decomposition of formic anhydride derivatives. Interestingly, the experimental results demonstrated that only certain types of formic anhydride derivatives can promote the hydrocarboxylation.9 Our calculation results shown in Scheme 4 revealed that formic anhydrides with electron-withdrawing groups (i.e., EWGs) have a significantly lower barrier for the decarbonylation process. In fact, a low barrier of decarbonylation implies a fast release of CO, which may poison the active nickel catalyst in a sealed tube. With the theoretical findings as inspiration, supplementary experiments carried out by our group showed that there was a clear picture of bubble release when CF3COOCHO is formed, while no obvious formation of gas was observed for AcOCHO. Further calculations confirmed our proposal that excess CO in the reaction system (a sealed tube) is indeed poisonous to the active Ni catalyst. As shown in Scheme 5, the enthalpy change of ligand exchange is up to +43.4 kJ/mol (with a free energy change of +62.2 kJ/mol), clearly indicating that the alkyne is a much weaker ligand in comparison to carbonyl (CO). Thus, if there is a higher concentration of CO, the fourth binding site (vacant site) of (dppbz)NiCO will be blocked for alkyne. Therefore, the existence of a large amount of CO can totally shut down the catalytic cycle. In combination with the

To avoid the problems caused by the overestimation of entropy (see the Supporting Information for more details), in this article, we decided to mainly use the enthalpy to discuss reaction pathways, with the calculated Gibbs energy shown in parentheses as a reference.21 All of the energies are relative to that of the intermediate intI. For those relatively flexible molecules, we have manually tested different conformers to confirm that the one involved in the calculated pathway has the lowest energy (see the Supporting Information for more information).

■

RESULTS AND DISCUSSION As shown in Scheme 2, our initial study commenced with the two-coordinate Ni(dppbz) complex int0, which was proposed in our experimental work. However, although the oxidative addition of HCOOH to Ni(0),22 the following hydride shift, and the CO insertion into the Ni(II)−C(sp2) bond are all proved feasible, this hydride transfer pathway is unfavored from the second catalytic cycle, as the final reductive elimination is very unlikely to happen (see the Supporting Information). At the initial catalytic cycle, a second CO molecule is vital to facilitating the reductive elimination. In fact, the reactive catalyst from the second catalytic cycle is a three-coordinate Ni complex (i.e., intI), in which a CO serves as the third ligand. Having established the active catalyst species involved in this novel Ni-catalyzed hydrocarboxylation reaction, we were then directed to depict a clear picture of the entire pathway. As presented in Scheme 3, the oxidative addition of formic acid to the Ni(0) does not exist in the new mechanism, as there is no vacant site to accommodate another formic acid. What is essentially different from the initial proposed mechanism is that there is no longer a hydride shift (hydrometalation), but an outer-sphere proton transfer from a loosely connected formic acid directly to the diphenylacetylene. The enthalpic barrier associated with the protonation is only 72.5 kJ/mol. Interestingly, such a van der Waals complex (intIII_vdW) is even more stable than the proposed four-coordinate Ni(0) complex in which a real Ni−O bond is involved (see the Supporting Information for more information). A recent literature report featuring a Ru−alkyne interaction suggests that the alkyne might be a four-electron donor, which interacts more strongly with the metal.23 It can also be seen from the initiation steps that the bidentate phosphine ligand dppbz is feasibly switchable from different ligation patterns (i.e., intII → intIII with an enthalpic barrier as low as +8.7 kJ/mol). Meanwhile, although an oxidative addition of a C−H bond (of formaldehyde) to Pd was reported to be plausible,24 our investigation indicated it cannot compete with the main reaction in our Ni system (see the Supporting Information for the details). Once the protonation is achieved, the generated intermediate intIV will undergo an intramolecular CO migration/insertion (via TSII) to afford int6, with a release of energy up to 48.5 kJ/ mol. As clearly marked in Scheme 3, the CO insertion should be a rapid reaction because the enthalpic barrier is as low as 13.7 kJ/mol. It is noteworthy at this stage that a direct reductive elimination happening between the alkenyl moiety and the formate is very unlikely due to a much higher barrier (associated with TSIII), which is due to the fact that both the alkenyl carbon and the O atom are negatively charged (−0.199 and −0.560, respectively, on the basis of an ESP charge analysis using the Merz−Kollman scheme28). Also, no such product was detected experimentally. C


Article

Organometallics

important conclusion can be drawn at this point: the barrier of decarbonylation must be compatible (or slightly higher) with that involved in the hydrocarboxylation, to prevent the Ni catalyst from being poisoned. In fact, the decarbonylation (i.e., thermolysis of formic anhydrides) is the rate-determining step of the entire reaction and controls the success of this Nicatalytic cycle. Meanwhile, the experimental observations indicated that the decomposition can be simply driven by heating, and the stability of formic anhydride derivatives varies with different −R groups.26 In fact, the decomposition (or decarbonylation) can be treated as a hydride shift process, in which the “hydride” of −CHO moves to the nearby acyl oxygen. The EWG group makes the acyl oxygen much more electron deficient, thus promoting and speeding up the hydride transfer (see the Supporting Information for more information about the ESP charge analysis). Thus, we realize at this stage that an EDG group is necessary to ensure a gradual release of CO. Our focus was then directed to explaining the ligand effect. Experimentally, simple monodentate ligands, for example PPh3, were found to be useless in promoting the hydrocarboxylation. With the newly discovered mechanism in hand, we would like to revisit the ligand effect in this reaction. According to our calculation results, changing the ligand to PPh3 does not significantly affect the final reductive elimination but the initial binding of alkynes (see the Supporting Information for more details). As shown in Scheme 7, the enthalpy is lowered by 55.2 kJ/mol for the binding of diphenylacetylene to Ni(dppbz), whereas the value is +1.3 kJ/mol for that of Ni(PPh3)2. Even if we take account of the empirically corrected Gibbs energy into consideration,21 the substitution is still more favored with a bidentate phosphine ligand. Thus, from an energy perspective, we know that a bidentate ligand can somehow facilitate the coordination of alkyne. In addition, inspection of the optimized structures of (Ph3P)2NiCO and (dppbz)NiCO disclosed a much smaller

Scheme 4. Enthalpic and Free Energy Barriers of the Decomposition of Formic Anhydride Derivatives

Scheme 5. Catalyst Poisoning for (dppbz)Ni(CO)

energy profile shown in Scheme 6, we now understand that the main reaction will pause at int6b and wait for the CO generated from the thermal decomposition of formic anhydrides. An

Scheme 6. Energy Profile of the Final Reductive Elimination (with int6b as the Resting State)

D


Article

Organometallics

the basis of our model reaction in which dppbz acts as the ligand), we can believe the existence of an even more stable int6c_PPh3 will add another 11.5 kJ/mol to the energetic span. The reaction may be therefore halted. Experimentally, a reactive C−X (X = halogen) bond, even the most reactive C−I bond, was found to be tolerated in this reaction (see Scheme S10 in the Supporting Information for reaction details).9 However, this inspiring experimental result raised another question for us to study: why there is no oxidative addition of the C−I bond to the Ni(0) complex? As shown in Scheme 8, the reaction pathway bifurcates at a very early point, with one branch leading to the oxidative addition of the C−I bond to the Ni(0) and the other going through the coordination of alkyne to the Ni atom. Calculations disclosed that the former pathway is more energy demanding, as the enthalpic barrier is up to 95.3 kJ/mol. From a chemical perspective, the stronger d−π* back-donation from Ni to CO in the newly found active catalyst intI is responsible for the lower reactivity of Ni(0) (see the Supporting Information for details of the proposed oxidative addition to int0 rather than intI). Such a bonding interaction significantly reduces the electron density on the Ni atom, making it less reactive toward oxidative addition. Meanwhile, our newly discovered protonation mechanism can adequately rationalize the experimental observation that no dehalogenated product was detected. If the reaction goes via the initially proposed hydride transfer mechanism, the Ni−H species will indeed dehalogenate the aryl iodide.27 Therefore, the experimental observations on the compatibility of C−X bonds, in turn, supported the reliability of the newly discovered mechanism. Extra efforts were also made to reveal the origin of regioselectivity. Since this reaction proceeds via a protonation rather than the proposed hydride transfer, Markovnikov’s rule should be applied here. As shown in Scheme 9, the barriers associated with the Markovnikov-type protonation and the antiMarkovnikov path are +80.8 and +89.3 kJ/mol, respectively. Moreover, the intermediate generated from the Markovnikovtype addition (i.e., intVa_M_H) is more stable than the other path (intVa_AntiM_H) by 6.3 kJ/mol, indicating a ratio of 12.6:1 at 298.15 K, which qualitatively fits the experimental observations (α:β = 68%:3%). The ESP charge analysis using the Merz−Kollman scheme28 on the prereaction complex intIIIa_H suggested that the terminal carbon is more negatively charged in comparison to the internal carbon (−0.365 vs −0.017). Along with the charge analysis, we have also performed a distortion/interaction analysis (also known as the activation strain model) on both transition states.29 With the details shown in Scheme S12 in the Supporting Information, we found that the interaction between the Nibound alkyne and formic acid is stronger in the Markovnikov type of protonation. Meanwhile, the distortion energies for both Ni complexes (Markovnikov and anti-Markovnikov) are similar, thus excluding the origin of steric effects on the regioselectivty. Inspection of the O−H and H−C distances pointed out a stronger H−Cterminal interaction. Therefore, both the charge analysis and the distortion/interaction analysis can explain the origin of the observed regioselectivity to some extent, which is mainly caused by electronic effects.

Scheme 7. Calculated Energy Change for Alkyne Coordination with dppbz and PPh3

(and indeed more distorted) P−Ni−P binding angle in the latter. The stronger ring strain on the five-membered ring is believed to benefit the cleavage of a Ni−P σ bond when necessary, making the dppbz switchable between monodentate ligation and bidentate ligation. From these results (see Scheme 7 and Figure 1), we envisaged that placing sterically bulky

Figure 1. P−Ni−P angles in two different catalysts (113.0 and 87.2°, respectively).

substituents on the bidentate phosphine may further promote the coordination of alkynes to Ni, facilitating reductive elimination, and hence improve the catalyst performance. Despite the differences in binding strength, the monodentate ligand can also help to form complexes in a trans configuration while the bidentate ligand can only form the cis isomers. Our calculations revealed a new trans resting state, which is more stable than its cis isomer. As seen in Figure 2, the intermediate int6_PPh3 can react with another PPh3 molecule to form either int6b_PPh3 or int6c_PPh3, and the energy of the latter is 11.5 kJ/mol lower than that of the former. Given the fact that the energetic span of the catalytic cycle was around 90 kJ/mol (on

■

CONCLUSIONS In conclusion, extensive DFT calculations have been carried out to reveal the mechanistic details of the novel Ni-catalyzed hydrocarboxylation reaction (Scheme 10). The fact that the

Figure 2. Optimized structures of int6_PPh3, int6b_PPh3 and int6c_PPh3. E


Article

Organometallics Scheme 8. Competitive Pathways with the Substrate Bearing a Reactive C−I Bond

Scheme 9. Regioselectivity of the Novel Ni-Catalyzed Hydrocarboxylation Reaction

controlled generation of carbon monoxide is crucial to a successful transformation was well interpreted by theoretical calculations as the formation of a monocarbonyl nickel(0) species. Though direct reductive elimination between the alkenyl moiety and the formate fragment is very unlikely from an energetic perspective, coordination of one CO to Ni(II) can greatly facilitate this process. The actual catalytic species involved in this reaction is found to be Ni(dppbz)CO rather than the two-coordinate Ni(dppbz) as proposed in previous experimental reports.9

Instead of the proposed hydride transfer mechanism, our calculation revealed an outer-sphere protonation pathway in which a proton is directly transferred from a loosely connected HCOOH to the alkyne. Moreover, due to the vital role of CO, the generating speed of CO must be compatible with the main reaction. A fast release of CO will fail to generate the product due to catalyst poisoning. The Ni catalytic cycle will pause at int6b (which acts as the resting state) and the CO generated in situ will take part in the reaction at this stage. In summary, the energetic span of the Ni catalytic cycle is 92.3 kJ/mol and the F


Organometallics Scheme 10. Mechanistic Details of the Ni Catalytic Cycle

Article

■

ACKNOWLEDGMENTS

■

REFERENCES

We thank the support from the National Natural Science Foundation of China (21325208, 21572212), Ministry of Science and Technology of China (2017YFA0303500), Chinese Academy of Science (XDB20000000), the Key Technologies R&D Programme of Anhui Province (1604a0702027), FRFCU and PCSIRT. The supercomputing center in the University of Science and Techonology of China is also acknowledged for providing computational resources.

(1) (a) Zeng, X. Chem. Rev. 2013, 113, 6864−6900. (b) Zhang, Y.; Riduan, S. N. Angew. Chem., Int. Ed. 2011, 50, 6210−6212. (c) Takaya, J.; Iwasawa, N. J. Am. Chem. Soc. 2008, 130, 15254−15255. (d) Zhu, C.; Takaya, J.; Iwasawa, N. Org. Lett. 2015, 17, 1814−1817. (e) Wang, Y.; Ren, W.; Li, J.; Wang, H.; Shi, Y. Org. Lett. 2014, 16, 5960−5963. (f) Ren, W.; Chang, W.; Wang, Y.; Li, J.; Shi, Y. Org. Lett. 2015, 17, 3544−3547. (g) Bertleff, W.; Roeper, M.; Sava, X. Ullmann’s Encyclopedia of Industrial Chemistry; Wiley-VCH: Weinheim, Germany, 2005. (h) Liu, Q.; Wu, L.; Jackstell, R.; Beller, M. Nat. Commun. 2015, 6, 5933. (i) Yu, D.; Teong, S. P.; Zhang, Y. Coord. Chem. Rev. 2015, 293−294, 279−291. (2) (a) Williams, C. M.; Johnson, J. B.; Rovis, T. J. Am. Chem. Soc. 2008, 130, 14936−14937. (b) Fujihara, T.; Xu, T.; Semba, K.; Terao, J.; Tsuji, Y. Angew. Chem., Int. Ed. 2011, 50, 523−527. (c) Li, S.; Yuan, W.; Ma, S. Angew. Chem., Int. Ed. 2011, 50, 2578−2582. (d) Tanaka, S.; Tanaka, Y.; Chiba, M.; Hattori, T. Tetrahedron Lett. 2015, 56, 3830−3834. (e) Tsuji, Y.; Fujihara, T. Chem. Commun. 2012, 48, 9956−9964. (3) (a) Kawashima, S.; Aikawa, K.; Mikami, K. Eur. J. Org. Chem. 2016, 2016, 3166−3170. (b) Ostapowicz, T. G.; Schmitz, M.; Krystof, M.; Klankermayer, J.; Leitner, W. Angew. Chem., Int. Ed. 2013, 52, 12119−12123. (c) North, M. Angew. Chem., Int. Ed. 2009, 48, 4104− 4105. (d) Sun, J.; Bao, M.; Feng, X.; Yu, X.; Yamamoto, Y.; Almansour, A. I.; Arumugam, N.; Kumar, R. S. Tetrahedron Lett. 2015, 56, 6747− 6750. (e) Greenhalgh, M. D.; Thomas, S. P. J. Am. Chem. Soc. 2012, 134, 11900−11903. (f) Shao, P.; Wang, S.; Chen, C.; Xi, C. Org. Lett. 2016, 18, 2050−2053. (g) Takimoto, M.; Hou, Z. Chem. - Eur. J. 2013, 19, 11439−11445. (h) Wang, X.; Nakajima, M.; Martin, R. J. Am. Chem. Soc. 2015, 137, 8924−8927. (i) Cao, T.; Ma, S. Org. Lett. 2016, 18, 1510−1513. (j) Dupuy, S.; Gasperini, D.; Nolan, S. P. ACS Catal. 2015, 5, 6918−6921. (4) (a) Jin, F.; Yun, J.; Li, G.; Kishita, A.; Tohji, K.; Enomoto, H. Green Chem. 2008, 10, 612−615. (b) Gao, P.; Li, G.; Yang, F.; Lv, X.; Fan, H.; Meng, L.; Yu, X. Ind. Crops Prod. 2013, 48, 61−67. (c) Jing, S.; Cao, X.; Zhong, L.; Peng, X.; Zhang, X.; Wang, S.; Sun, R. ACS Sustainable Chem. Eng. 2016, 4, 4146−4155. (d) Reichert, J.; Brunner, B.; Jess, A.; Wasserscheid, P.; Albert, J. Energy Environ. Sci. 2015, 8, 2985−2990. (5) (a) Fujii, A.; Hashiguchi, S.; Uematsu, N.; Ikariya, T.; Noyori, R. J. Am. Chem. Soc. 1996, 118, 2521−2522. (b) Richmond, E.; Moran, J. J. Org. Chem. 2015, 80, 6922−6929. (c) Shende, V. S.; Deshpande, S. H.; Shingote, S. K.; Joseph, A.; Kelkar, A. A. Org. Lett. 2015, 17, 2878− 2881. (d) Wu, X.; Liu, J.; Li, X.; Zanotti-Gerosa, A.; Hancock, F.; Vinci, D.; Ruan, J.; Xiao, J. Angew. Chem., Int. Ed. 2006, 45, 6718− 6722. (e) Soltani, O.; Ariger, M. A.; Vázquez-Villa, H.; Carreira, E. M. Org. Lett. 2010, 12, 2893−2895. (f) Zhang, D.; Cheng, T.; Zhao, Q.; Xu, J.; Liu, G. Org. Lett. 2014, 16, 5764−5767. (6) Shen, R.; Chen, T.; Zhao, Y.; Qiu, R.; Zhou, Y.; Yin, S.; Wang, X.; Goto, M.; Han, L. − B. J. Am. Chem. Soc. 2011, 133, 17037−17044. (7) (a) Wu, L.; Liu, Q.; Jackstell, R.; Beller, M. Angew. Chem., Int. Ed. 2014, 53, 6310−6320. (b) Zargarian, D.; Alper, H. Organometallics 1993, 12, 712−724. (c) El Ali, B.; Alper, H. J. Org. Chem. 1993, 58, 3595−3596. (d) Vasapollo, G.; Somasunderam, A.; El Ali, B.; Alper, H. Tetrahedron Lett. 1994, 35, 6203−6206. (8) (a) Hou, J.; Xie, J.; Zhou, Q. Angew. Chem., Int. Ed. 2015, 54, 6302−6305. (b) Dai, J.; Ren, W.; Wang, H.; Shi, Y. Org. Biomol. Chem.

barrier of the thermal decomposition of formic anhydride is around 110 kJ/mol. Thus, the rate-determining step of this hydrocarboxylation should be the thermolysis of formic anhydrides. The reason for the better performance of a bidentate phosphine ligand can be ascribed to its unique ligation pattern.30 A bidentate phosphine ligand was found to benefit the alkyne coordination, as well as to avoid the formation of an even more stable resting state in a trans configuration. This newly uncovered mechanism also helps to rationalize several intriguing experimental observations, such as the origins of regioselectivity and the compatibility of C−X (X = Br, I) bonds. We hope these studies can offer useful mechanistic insights for catalyst design in this field.

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.organomet.7b00310. Additional schemes and discussions as detailed in the text (PDF) Cartesian coordinates for the calculated structures (XYZ)

■

AUTHOR INFORMATION

Corresponding Authors

*E-mail for R.S.: [email protected]. *E-mail for Y.F.: [email protected]. ORCID

Rui Shang: 0000-0002-2513-2064 Yao Fu: 0000-0003-2282-4839 Present Address †

R.S.: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 1130033, Japan. Notes

The authors declare no competing financial interest. G


Article

Organometallics

(29) (a) Medina, J. M.; Mackey, J. L.; Garg, N. K.; Houk, K. N. J. Am. Chem. Soc. 2014, 136, 15798−15805. (b) Wolters, L. P.; Bickelhaupt, F. M. WIREs Comput. Mol. Sci. 2015, 5, 324−343. (c) Bickelhaupt, F. M.; Houk, K. N. Angew. Chem., Int. Ed. 2017, DOI: 10.1002/ anie.201701486. (30) (a) Shang, R.; Ilies, L.; Matsumoto, A.; Nakamura, E. J. Am. Chem. Soc. 2013, 135, 6030−6032. (b) Shang, R.; Ilies, L.; Asako, S.; Nakamura, E. J. Am. Chem. Soc. 2014, 136, 14349−14352.

2015, 13, 8429−8432. (c) Wang, Y.; Ren, W.; Shi, Y. Org. Biomol. Chem. 2015, 13, 8416−8419. (9) (a) Fu, M.; Shang, R.; Cheng, W.; Fu, Y. ACS Catal. 2016, 6, 2501−2505. (b) Hou, J.; Yuan, M.; Xie, J.; Zhou, Q. Green Chem. 2016, 18, 2981−2984. (10) Tsou, T. T.; Kochi, J. K. J. Am. Chem. Soc. 1979, 101, 6319− 6332. (11) (a) Becke, A. D. Phys. Rev. A: At., Mol., Opt. Phys. 1988, 38, 3098−3100. (b) Becke, A. D. J. Chem. Phys. 1993, 98, 1372−1377. (c) Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B: Condens. Matter Mater. Phys. 1988, 37, 785−789. (12) Grimme, S.; Anthony, J.; Ehrlich, S.; Krieg, H. J. Chem. Phys. 2010, 132, 154104−1−154104−19. (13) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A., Jr.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, M. J.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, Ö .; Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian 09, Revision D.01; Gaussian, Inc., Wallingford, CT, 2009. (14) Krishnan, R.; Binkley, J. S.; Seeger, R.; Pople, J. A. J. Chem. Phys. 1980, 72, 650−654. (15) Dolg, M. Theor. Comput. Chem. 2002, 11, 793−862. (16) (a) Hollwarth, A.; Böhme, M.; Dapprich, S.; Ehlers, A. W.; Gobbi, A.; Jonas, V.; Köhler, K. F.; Stegmann, R.; Veldkamp, A.; Frenking, G. Chem. Phys. Lett. 1993, 208, 237−240. (b) Ehlers, A. W.; Böhme, M.; Dapprich, S.; Gobbi, A.; Höllwarth, A.; Jonas, V.; Köhler, K. F.; Stegmann, R.; Veldkamp, A.; Frenking, G. Chem. Phys. Lett. 1993, 208, 111−114. (17) (a) Peng, C.; Schlegel, H. B. Isr. J. Chem. 1993, 33, 449−454. (b) Peng, C.; Ayala, P. Y.; Schlegel, H. B.; Frisch, M. J. J. Comput. Chem. 1996, 17, 49−56. (18) Schlegel, H. B. J. Comput. Chem. 1982, 3, 214−218. (19) (a) Mennucci, B.; Tomasi, J. J. J. Chem. Phys. 1997, 106, 5151− 5158. (b) Cossi, M.; Barone, V.; Mennucci, B.; Tomasi, J. Chem. Phys. Lett. 1998, 286, 253−260. (c) Cossi, M.; Scalmani, G.; Rega, N.; Barone, V. J. J. Chem. Phys. 2002, 117, 43−54. (20) Fukui, K. Acc. Chem. Res. 1981, 14, 363−368. (21) For detailed discussions and references on the entropy issue, please refer to the Supporting Information. (22) Amatore, C.; Jutand, A.; Meyer, G.; Carelli, I.; Chiarotto, I. Eur. J. Inorg. Chem. 2000, 2000, 1855−1859. (23) Roşca, D. − A.; Radkowski, K.; Wolf, L. M.; Wagh, M.; Goddard, R.; Thiel, W.; Fürstner, A. J. Am. Chem. Soc. 2017, 139, 2443−2455. (24) Liu, Q.; Yuan, K.; Arockiam, P. − B.; Franke, R.; Doucet, H.; Jackstell, R.; Beller, M. Angew. Chem., Int. Ed. 2015, 54, 4493−4497. (25) (a) Kozuch, S.; Shaik, S. Acc. Chem. Res. 2011, 44, 101−110. (b) Kozuch, S.; Martin, J. M. L. ChemPhysChem 2011, 12, 1413−1418. (c) Kozuch, S. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2012, 2, 795− 815. (26) McGarvey, G. J.; Hiner, R. N.; Williams, J. M.; Matasubara, Y.; Poarch, J. W. J. Org. Chem. 1986, 51, 3742−3744. (27) (a) Á lvarez-Bercedo, P.; Martin, R. J. Am. Chem. Soc. 2010, 132, 17352−17353. (b) Tobisu, M.; Nakamura, K.; Chatani, N. J. Am. Chem. Soc. 2014, 136, 5587−5590. (c) Yi, Y.; Yang, W.; Zhai, D.; Zhang, X.; Li, S.; Guan, B. Chem. Commun. 2016, 52, 10894−10897. (28) (a) Singh, U. C.; Kollman, P. A. J. Comput. Chem. 1984, 5, 129− 145. (b) Besler, B. H.; Merz, K. M.; Kollman, P. A. J. Comput. Chem. 1990, 11, 431−439. H


Theoretical Investigation on Nickel-Catalyzed ... - ACS Publications

Recommend Documents