LiClO4-catalysed C-alkylation of pyrrole and indoles with aziridines and epoxides

Abstract

Aryl-N-tosylaziridines and epoxides smoothly undergo ring-opening with pyrrole and indoles in the presence of 5M lithium perchlorate in diethyl ether (LPDE) at ambient temperature to afford the corresponding 2- and 3-alkylated pyrroles and 3-alkylated indoles in high yields with high selectivity. LiOTf is also found to be an effective catalyst for this transformation.