Ag^I‐Promoted Cascade for Difluoromethylation of Activated Alkenes to Difluoromethylated Oxindoles

Abstract

A simple Ag I ‐mediated direct difluoromethylation reaction of activated alkenes by using TMSCF 2 COOEt (TMS = trimethylsilyl) under mild reaction conditions has been described. This reaction tolerates a variety of functional groups and allows for a highly efficient synthesis of various difluoro‐containing oxindoles. Mechanistic investigations indicate that a difluoromethyl radical initiated the cascade sequence by undergoing an addition reaction to the alkene.