Chemo- and enantioselective hetero-coupling of hydroxycarbazoles catalyzed by a chiral vanadium(v) complex†
The catalytic enantioselective oxidative hetero-coupling of arenols using a chiral vanadium(V) complex has been developed. The coupling of hydroxycarbazole derivatives with various arenols provided axially chiral biarenols with high chemo-, regio-, and enantioselectivities. The reaction took place under mild conditions and exhibited satisfactory functional group tolerance. Aerobic oxidative hetero-coupling with β-ketoesters also proceeded with high chemo- and stereoselectivities under slightly modified reaction conditions.