Visible Light Promoted Site‐Specific Functionalization of α‐Acyloxy Carboxamides: Unlocking a Forbidden Chemical Space in the Passerini Reaction

The facile generation of the α‐acyloxy carboxamide radical is hereby reported for the first time, utilizing a photoredox catalyzed reaction of Passerini adducts synthesized using a 4‐formyl‐1,4‐dihydropyridine as the carbonyl component. This radical effectively engages in a Giese reaction with a range of olefins, ultimately leading to the synthesis of novel Passerini‐derived products not previously amenable to direct aldehyde‐based transformations. Consequently, the resulting strategy, developed both in batch and in flow, offers a promising opportunity to expand the chemical space accessible through the Passerini reaction, virtually incorporating “impossible” aldehydes. A novel method is presented, demonstrating the facile generation of α‐acyloxy carboxamide radicals via photoredox catalysis of Passerini adducts, obtained employing a 4‐formyl‐1,4‐dihydropyridine. These radicals efficiently undergo Giese reactions with various olefins, yielding novel Passerini compounds unattainable through traditional aldehyde‐based routes.