Photoexcited Copper-Catalyzed Enantioselective Allylic C(sp)-H Acyloxylation of Acyclic Internal Alkenes.

The functionalization of C-H bonds streamlines the synthesis of complex molecules by eliminating the need for substrate preactivation. Traditionally, the Kharasch-Sosnovsky reaction, which directly oxidizes allylic C-H bonds into allylic esters under copper catalysis, has been hampered by long reaction times, limited substrate scope, and low enantioselectivity with acyclic olefins. Herein, we present a novel, visible light-driven, copper-catalyzed asymmetric Kharasch-Sosnovsky reaction that overcomes these challenges. This method expands the substrate scope to include acyclic internal alkenes and improves reaction conditions using eco-friendly visible light catalysis. It enhances radical reactivity and achieves superior enantioselectivity and regioselectivity in producing allylic C-H acyloxylation products. This breakthrough significantly advances direct C-H functionalization techniques, offering a more efficient and sustainable approach to synthesizing chiral molecules.