α‐Acylation of Alkenes by a Single Photocatalyst

Abstract

AbstractA direct strategy for the difunctionalization of alkenes, with acylation occurring at the more substituted alkene position, would be attractive for complex ketone synthesis. We report herein a reaction driven by a single photocatalyst that enables α‐acylation in this way with the introduction of a fluoromethyl, alkyl, sulfonyl or thioether group at the β‐position of the alkene with high chemo‐ and regioselectivity under extremely mild conditions. Crucial to the success of this method are rate differences in the kinetics of radical generation through single‐electron transfer (SET) between different radical precursors and the excited photocatalyst (PC*). Thus, the β‐position of the alkene is first occupied by the group derived from the radical precursor that can be generated most readily, and α‐keto acids could be used as an electrophilic reagent for the α‐acylation of alkenes.