Visible Light‐Promoted Enantioselective Catalytic Alkylation of α‐Ketoamides with Hydrocarbons

Visible light‐mediated enantioselective alkylation of carbonyls with hydrocarbons provides a beneficial access to the synthesis of chiral alcohols in terms of atom economy. Herein, we disclosed a direct asymmetric alkylation of a‐keto pyrazoleamides with hydrocarbons as C(sp3)–H donors for the preparation of tertiary a‐hydroxy amides. Our method operates by synergistic catalysis involving Ir‐based photoredox catalyst and chiral N,N′‐dioxide‐NiBr2 complex enabled the addition reaction in good to excellent yield and enantioselectivity (up to 87% yield and 97% ee), competing successfully with the homocouplings. Based on the control experiments and spectrographic experiments, a possible radical addition mechanism triggered by Ir photoredox catalysis and bromine radical‐participated hydrogen atom transfer of hydrocarbon was proposed.