Isothiourea-Catalyzed Synthesis of Pyrrole- and Indole-Functionalized Tetrasubstituted Pyridines

Abstract

The generation of pyrrole- and indole-functionalized tetrasubstituted pyridines in a one-pot process from 2-(pyrrol-1-yl)acetic acid or 2-(indol-1-yl)acetic acid and α,β-unsaturated N-sulfonyl-ketimines is described. The process is proposed to operate via an isothiourea-catalyzed Michael addition-lactamization, followed by elimination of sulfinic acid and O-acylation to provide the final pyridine product.