Synthesis of 2,3-Disubstituted Pyrroles by Lewis Acid Promoted Cyclization of N-Sulfonyl Vinylogous Carbamates and Amides

Tetrahedron Lett. 2023 Jun 6:122:154507. doi: 10.1016/j.tetlet.2023.154507. Epub 2023 Apr 19.

Abstract

A three-step sequence to construct pyrroles from three components including 2,2-dimethoxyethylamine, aryl/alkyl sulfonyl chlorides and alkynes bearing electron-withdrawing groups is presented. The pyrroles are proposed to arise via a 5-exo-trig cyclization proceeding through both oxocarbenium and N-sulfonyliminium ions. This modular route allows for the variability at the N-sulfonyl group, the C2 and C3 substituents for rational vectoring of the pyrrole nucleus for downstream processes.