General and efficient access to homoallyl amines via single-electron-transfer reduction-induced E1cb elimination reaction.

Herein, we report new photoredox-catalyzed elimination reactions based on the reductive radical-polar crossover process. Under the visible-light-mediated photoredox-catalyzed reaction conditions, a range of amine derivatives bearing various functional groups were used as effective radical precursors for generating α-aminoalkyl radicals. Structurally diverse homoallyl amines were efficiently prepared via the reactions of α-aminoalkyl radicals with allyl ethers or alcohols as radical acceptors. Mechanistic studies suggest that a radical addition/single-electron-transfer reduction/elimination cascade process was involved. This novel SET-reduction-induced E1cb-type elimination reaction features a broad substrate scope, good functional-group compatibility, and mild reaction conditions.