Enantioselective functionalization of unactivated C(sp3)–H bonds through copper-catalyzed diyne cyclization by kinetic resolution

Abstract

Site- and stereoselective C–H functionalization is highly challenging in the synthetic chemistry community. Although the chemistry of vinyl cations has been vigorously studied in C(sp3)–H functionalization reactions, the catalytic enantioselective C(sp3)–H functionalization based on vinyl cations, especially for an unactivated C(sp3)–H bond, has scarcely explored. Here, we report an asymmetric copper-catalyzed tandem diyne cyclization/unactivated C(sp3)–H insertion reaction via a kinetic resolution, affording both chiral polycyclic pyrroles and diynes with generally excellent enantioselectivities and excellent selectivity factors (up to 750). Importantly, this reaction demonstrates a metal-catalyzed enantioselective unactivated C(sp3)–H functionalization via vinyl cation and constitutes a kinetic resolution reaction based on diyne cyclization. Theoretical calculations further support the mechanism of vinyl cation-involved C(sp3)–H insertion reaction and elucidate the origin of enantioselectivity.