Photoinduced copper-catalyzed asymmetric radical three-component cross-coupling of 1,3-enynes with oxime esters and carboxylic acids†
Abstract
Catalytic radical difunctionalization of 1,3-enynes has recently been established as a potentially robust platform for construction of valuable allenes and propargylic compounds. Despite the considerable advances made in the realm of radical 1,4-difunctionalizations, there has been little progress in the radical 1,2-difunctionalizations, particularly regarding enantioselective variants. Herein, we report the first regio- and enantioselective radical three-component coupling of 1,3-enynes, oxime esters, and carboxylic acids through photoinduced copper catalysis. This redox-neutral protocol proceeds under mild conditions and demonstrates good functional group tolerance and 1,2-regioselectivity, providing access to a library of valuable cyanoalkylated propargylic esters with generally excellent enantioselectivity (>60 examples; up to 99% ee).