Photocatalytic Radical Decarboxylation [4 + 3] Annulation Reactions of Lactones via Dienoic Acid EDA Complexes

Abstract

The process of radical decarboxylation is crucial in organic synthesis. Nevertheless, decarboxylation of dienoic acids presents a greater challenge compared to that of aliphatic carboxylic acids. Herein, catalyst-and additive-free visible-lightpromoted [4 + 3] annulation of lactones and diamines was achieved via radical decarboxylation of dienoic acids. By means of this novel EDA-activated [4 + 3] annulation, the 1,5benzodiazepines, which display a wide range of biological activities and are widely used in many fields, can be directly accessed in high yields under mild conditions. This visible-light-induced radical decarboxylation [4 + 3] annulation tolerates a broad array of functional groups and intricate molecules, including pharmaceutical-relevant compounds and natural products.