Nickel Catalyzed Alkylation of Oxindoles with Alkyl Alcohols

Alkylation with alcohols: Herein, nickel-catalyzed hydrogen borrowing strategy was employed for alkylation of 2-oxindoles using alkyl alcohols. Initial mechanistic studies, deuterium labelling experiments and late stage synthetic modulation of the alkylated products were performed.

Abstract

Herein, a simple and efficient nickel-catalyzed C-3-selective alkylation of 2-oxindoles using primary alkyl and allylic alcohols have been demonstrated. The catalytic protocol enables transformations in the presence of free hydroxyl group, amine, cycloalkanes, olefins, and lactam including more challenging C2-C4 alcohols, citronellol and oleic acid derived alcohol in up to 96 % yield. Initial mechanistic studies and deuterium labelling experiments were performed. Synthetic modulations of the lactam enabled new routes for the synthesis of C-3-substituted indoles, indolines, and un-symmetric urea derivatives.

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