Nickel-Catalyzed Alkylation of Oxindoles with Secondary Alcohols
作者:Atanu Bera、Adrija Ghosh、Debasis Banerjee
DOI:10.1021/acs.joc.3c00402
日期:2023.6.2
we have demonstrated a simple nickel-catalyzed C-3-selective alkylation of 2-oxindoles using a wide variety of secondary alkyl alcohols. As a special highlight, functionalization of the cholesterol derivative was reported. Control experiments, initial mechanistic studies, and deuterium-labeling experiments were performed for the alkylation process.
Oxindoles have been successfully alpha-alkylated under Cp*Co-III catalysis by a vast array of secondary alcohols, including cyclic, acyclic, symmetrical, and unsymmetrical, to produce C-alkylated oxindoles. This protocol was also extended to the alpha-alkylation of N,N-dimethyl barbituric acid and benzyl cyanides. The kinetic profile and other preliminary mechanistic investigations suggest a first-order reaction rate in oxindoles and catalysts. A plausible catalytic cycle is proposed on the basis of the kinetic profile, of other preliminary mechanistic investigations, and of previous mechanistic studies on similar transformations, whereas density functional theory calculations provide insight into the nature of the active species.