Jingping Zhang
Northeast Normal University, China
Title: Mechanistic investigation inspired economic synthesis of pyrrole derivatives
Biography
Biography: Jingping Zhang
Abstract
DFT investigations are carried out to improve the domino cyclization between gem-dialkylthio vinylallenes and benzylamine (BnNH2)[1,2]. Economic reaction approaches were explored, namely, this reaction can occur under organic solvent-free conditions either catalyzed by trace water or self-catalyzed by BnNH2. Three types of reactions (DMSO-assisted, trace water-catalyzed, and self-catalyzed by BnNH2) shared the same reaction mechanism with the nucleophilic attack of BnNH2 on the allenic carbon of thioamide intermediate Re. For trace water-catalyzed reaction another mechanism was also found that the BnNH2 attacks the carbonyl carbon of the conformational isomer of Re. Among the investigated mechanisms, the trace water catalyzed one is suggested to be the most efficient and convenient synthetic method for pyrroles. Therefore, organic solvent DMSO is not necessary for this reaction, which is further verified by the experimental outcome. Our finding suggests more green chemistry reaction processes by either a trace water catalyst or BnNH2 self-catalyst and opens a new synthetic strategy for pyrrole derivatives.