Photocatalytic Enantioselective Radical Cascade Multicomponent Minisci Reaction of β-Carbolines Using Diazo Compounds as Radical Precursors

Abstract

Here, a photocatalytic asymmetric multicomponent cascade Minisci reaction of β-carbolines with enamides and diazo compounds is reported, enabling an effective enantioselective radical C─H functionalization of β-carbolines with high yields and enantioselectivity (up to 83% yield and 95% ee). This enantioselective multicomponent Minisci protocol exhibits step economy, high chemo-/enantio-selective control, and good functional group tolerance, allowing access to a variety of valuable chiral β-carbolines. Notably, diazo compounds are suitable radical precursors in enantioselective cascade radical reactions. Moreover, the efficiency and practicality of this approach are demonstrated by the asymmetric synthesis of bioactive compounds and natural products.

Keywords: Minisci reaction; asymmetric photocatalysis; diazo compounds; multicomponent reaction; radical cascade.