Visible Light Photoredox-Catalyzed Difunctionalization of (α-Substituted) N-Aryl Glycines with α-Bromoacetates: An Annulation Method for the Synthesis of 3-Substituted 2-Oxindoles via Decarboxylation/Aryl ortho-C-H Activation.

A novel and green approach for difunctionalization of (α-substituted) N-aryl glycines with α-bromoacetates via decarboxylation/aryl C-H activation was established under visible light photoredox catalysis. The protocol provided efficient access to desired products 3-substituted-2-oxindoles in moderate to excellent yields with good functional group tolerance. Mechanistic studies revealed that the transformation proceeded via a radical pathway with the aminomethyl and difluoromethyl radicals as key intermediates.