Palladium-Catalyzedand Photoinduced Site-SelectiveAlkynylation and Oxidation of the Remote C(sp³)–H

A general and efficient method for the direct alkynylation and oxidation of remote C­(sp³)–H bonds under photoirradiation is described. In this reaction, the Pd catalyst acts as both a photocatalyst to generate the nitrogen radical and a cross-coupling catalyst with a terminal alkyne. Attractive features of this system include good functional group tolerance, scalability, convenient reagents, and an operating system. The utility of this protocol is highlighted by its application for derivatization of several valuable aza-heterocycles such as caspase-3 inhibitor and azepinone derivatives.