DFT Studies on Ni-Mediated C–F Cleavage for the Synthesis of Cyclopentadiene Derivatives

Abstract

Density functional theory calculations have been performed to study the detailed mechanism of Ni-mediated [3+2] cycloaddition of 2-trifluoromethyl-1-alkenes with alkynes via cleavage of two C-F bonds. It was found that the reaction pathway involves oxidative cyclization, the first β-fluorine elimination, and then intramolecular 5-endo insertion of difluoroalkene, followed by the second cleavage of C-F bond, and finally the dissociation of difluorides yields the fluorine-containing product cyclopentadienes in sequence. The overall rate-determining step is the combined processes of the β-fluorine elimination and the 5-endo insertion. Furthermore, we investigated the effect of different ligands and the regioselectivity of asymmetric alkynes. The detailed energy profiles and structures are presented in this study.

Nickel‐Catalyzed Unsymmetrical Bis‐Allylation of Alkynes

“…[11o, 16] Initially, the oxidative cyclometallation of alkyne 1 a and αtrifluoromethylstyrene 2 a with Ni 0 gives nickelacycle A, which favors the syn-addition of alkyne bonds. In addition, based on previous DFT calculation, [17] phenyl group is more electron-deficient and makes its β-carbon relatively electron poorer. Therefore, the nickel metal tends to couple with the Ph-substituted carbon when using aryl-alkyl alkyne substrates.…”

Theoretical Insight into the Palladium-Catalyzed Prenylation and Geranylation of Oxindoles with Isoprene

“…An alternative mechanism for the formation of F′ is also considered based on the investigation by Huang et al 71 for the cyclization reaction of 2-trifluoromethyl-1-alkene with alkyne under Ni catalysis. In this mechanism, F′ is formed via initial protonation-oxidation, followed by an alkene migration insertion and isomerization step, as shown in Scheme S1.…”

Advances in Sustainable Catalysis: A Computational Perspective

“…Achieving all these goals will require the design of novel and efficient catalysts that are active under mild conditions and can be produced sustainably without leading to unacceptably high levels of toxic pollutants (Beletskaya and Kustov, 2010; Polshettiwar and Varma, 2010; Chua and Pumera, 2015; Egorova and Ananikov, 2016). However, before any of these new catalysts can be developed a fundamental understanding of the properties of the currently most efficient and environmentally sustainable options has to be obtained, in order to enable the design of their replacement (Campbell et al, 2016; Hutchings et al, 2016; Pelletier and Basset, 2016; Friend and Xu, 2017; Chen et al, 2018; Kornienko et al, 2018; Caddell Haatveit et al, 2019). Computational models have proved to be one of the most efficient and least resource heavy ways of obtaining such information and have now become an invaluable component in the field as a whole (Nørskov et al, 2009; Hansgen et al, 2010; Medford et al, 2015; Sutton and Vlachos, 2015; Greeley, 2016; Grajciar et al, 2018).…”