A novel photoinduced strategy has been developed for the C–H amidation of aromatics and heteroaromatics by using benzamide radicals with free NH groups generated from N-amidopyridinium salts under visible-light irradiation. The new mode of activation of N-amidopyridinium salts proceeds efficiently under mild conditions to give various benzamide derivatives with free NH groups. In addition, oxazoline analogues, synthesized by the reaction with styrene, demonstrate a substantial range of prospective applications for this versatile protocol.
Key words
photocatalysis - amidopyridinium salts - amidation - [3+2]-annulation - radical reactions