Regioselective construction of 2-substituted indolines enabled by a rhodium-catalyzed decarboxylation–hydroacylation sequence

Abstract

Herein, we describe the first rhodium(I)-catalyzed decarboxylative cyclization and hydroacylation of vinyl benzoxazinanones with chelating aldehydes, allowing a straightforward and efficient synthesis of 2-substituted indolines in moderate to good yields with excellent regioselectivity. Of note, the mechanistic proposal indicates that a new intermediate featuring η²-coordination may be in situ generated through a nucleophilic attack at the central carbon of the π-allylmetal intermediate followed by reductive elimination. This study provides unique insights into the reactivity of π-allylmetal species that can be used in hydrofunctionalization.