Enantioselective Decarboxylative C(sp3)-C(sp3) Cross-Coupling of Aliphatic Acids with gem-Borazirconocene Alkanes

Asymmetric decarboxylative cross-couplings of carboxylic acids represent a powerful tool to synthesize chiral building blocks for medicinal chemistry and material science. However, synthesis of versatile chiral alkylboron derivatives via asymmetric decarboxylative C(sp3)-C(sp3) cross-coupling from readily available primary aliphatic acids and mild organometallic reagents is still challenging. In this study, we report a visible-light-induced, Ni-catalyzed enantioconvergent C(sp3)-C(sp3) cross-coupling of unactivated primary aliphatic acids with gem-borazirconocene alkanes, furnishing a diverse array of valuable chiral alkylboron building blocks. The broad substrate scope, high functional group tolerance, and the late-stage modification of complex drug molecules and natural products with high enantioselectivity demonstrate the synthetic potential of the method. Mechanistic investigations suggest an enantioconvergent radical-radical cross-coupling pathway, wherein the primary radical from carboxylic acids is generated through single-electron reduction with ZrIII species, representing an unprecedented example of enantioselective radical C(sp3)-C(sp3) cross coupling in the absence of photocatalysts.