Hydrogen Atom Transfer-Triggered Enantioselective Hydroalkylation of 1,3-Enynes to Chiral Allenes

Abstract

Asymmetric radical addition to 1,3-enynes represents an efficient strategy for the construction of chiral allenes. Current methods typically rely on prefunctionalized radical precursors and electron-rich 1,3-enynes. Herein, we report a photoinduced enantioselective 1,4-radical hydroalkylation of 2-acyl 1,3-enynes with inert C(sp3)–H compounds. Synergistic catalysis merging a quinone-based hydrogen atom transfer photocatalyst with a chiral N,N′-dioxide/Sc(III) complex was exploited to enable the straightforward synthesis of chiral allenes in high yield and enantioselectivity.