Photoredox nickel-catalyzed radical cyclization of N-arylacrylamides with alkyl bromides†

Abstract

3,3-Disubstituted oxindoles constitute a significant class of biologically active molecules, often found in a wide range of bioactive compounds. In this work, we present a photoredox nickel-catalyzed intermolecular cyclization between N-arylacrylamides and readily accessible alkyl bromides, which affords a diverse range of 3,3-disubstituted oxindoles in moderate to high yields. Our mechanistic studies reveal that the reduction of alkyl bromides via single-electron transfer from a reactive Ni(i) species is a critical step in driving this radical cascade transformation. This approach offers several advantages, including mild reaction conditions, broad functional group tolerance, and a simple workup procedure.