Allylation, Alkenylation, and Alkynylation of Monofluoromethyl Ketyl Radical Enabled by Photoredox Halogen-Atom-Transfer

Abstract

In this study, we disclose an innovative strategy to access α-monofluoromethyl secondary alcohol derivatives under mild blue-light irradiation from brominated fluoroethanol benzoate (BFEB). This reaction takes advantages of bulky silicon radical as a halogen atom transfer (XAT) acceptor to generate the nucleophilic monofluoromethyl ketyl-type radical, which serves as the key intermediate to couple with a series of phenylsulfonyl-masked substrates. A broad scope of allyl, alkenyl (Z and E configurations), and alkynyl α-monofluoromethyl carbinol derivatives were obtained in moderate to good yields.