Mechanistic study of the cooperative palladium/Lewis acid-catalyzed transfer hydrocyanation reaction: the origin of the regioselectivity

Dandan Jiang^‡a, Xiaojun Li^‡a, Jiali Cai^a, Yuna Bai^a, Lixiong Zhang^b, Lili Zhao^a*

^aInstitute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China. E-mail: ias_llzhao@njtech.edu.cn

^bCollege of Chemical Engineering, State Key Laboratory of Materials-Oriented

Chemical Engineering, Nanjing Tech University, Nanjing 211816, China

Abstract: Density functional theory (DFT) calculations have been performed to gain insight into the catalytic mechanism of the Palladium/Lewis acid-catalyzed transfer hydrocyanation of terminal alkenes to reach the linear alkyl nitrile with excellent anti-Markovnikov selectivity. The study reveals that the whole catalysis can be characterized via three stages: (i) oxidative addition generates the π-allyl complex IM2, followed by the β-hydride elimination leading to intermediate IM4. (ii) ligand exchange followed by Pd-H migratory alkene insertion gives the anti-Markovnikov intermediate IM6. (iii) IM6 undergoes reductive elimination step for the linear terminal nitrile 3a and regenerate the active species for the next catalytic cycle. Each stage is kinetically and thermodynamically feasible. The oxidative addition step, with a barrier of 30.9 kcal mol^-1, should be the rate-determining step (RDS) in the whole catalysis, which agrees with the experimental high temperature of 110 ^oC. Furthermore, the origin of the high regioselectivity of the product with excellent anti-Markovnikov selectivity is discussed.

Dalton Trans., 2021, 50,1233  影响因子：4.174

论文链接：https://pubs.rsc.org/en/content/articlelanding/2021/DT/D0DT03941A#!divAbstract