<scp>Visible‐Light‐Mediated Photocatalyst‐Free</scp> Hydroacylation of Azodicarboxylic Acid Derivatives with <scp>4‐Acyl</scp>‐1,4‐dihydropyridines
Li Liu, Jing Wang, Xiaoying Feng, Kun Xu, Wei Liu, Xia Peng, Hongguang Du, Jiajing Tan
Abstract
Comprehensive Summary A visible‐light‐enabled, photocatalyst‐free hydroacylation reaction of azodicarboxylic acid derivatives was described. This radical conjugate addition (RCA) protocol relied on the dual role of 4‐acyl‐1,4‐dihydropyridine (acyl‐DHP) reagents that besides being as radical reservoirs, they also enabled the conversion of radical adducts to anion intermediates via reduction. Under “catalyst‐oxidant‐additive free” conditions, a wide range of structurally different acyl hydrazide products were readily obtained in 56%—99% yields. The utility of this transformation was further demonstrated by the scale‐up synthesis and downstream derivatization.