Synthesis of 1,7-Annulated Indazole Derivatives via Bifunctional Brønsted Base Catalyzed Cascade Reaction

Abstract

A novel method for the asymmetric synthesis of 1,7-annulated indazoles has been developed via bifunctional Brønsted base catalyzed cascade reaction. This process enabled the formation of multiple chiral centers including a quaternary carbon center in high yields with excellent diastereoselectivities and enantioselectivities. The reaction exhibited broad functional group tolerance and mild reaction conditions.