An N‐Trifluoromethylation/Cyclization Strategy for Accessing Diverse N‐Trifluoromethyl Azoles from Nitriles and 1,3‐Dipoles

Abstract

AbstractN‐Trifluoromethyl azoles are valuable targets in medicinal chemistry, but their synthesis is challenging. Classical preparation of N‐CF3 azoles relies on the functional group interconversions but suffers from tedious N‐pre‐functionalization and unfriendly agents. Introduction of the CF3 onto the nitrogen of heterocycles provides a direct route to such motifs, but the N‐trifluoromethylation remains underdeveloped. Reported here is an alternative and scalable cyclization strategy based on NCF3‐containing synthons for constructing N‐CF3 azoles. The approach involves the N‐trifluoromethylation of nitriles followed by a [3+2] cyclization between resulting N‐CF3 nitrilium derivatives and 1,3‐dipoles. PhICF3Cl was an effective CF3 source for the transformation. As a result, a generic platform is established to divergently synthesize N‐trifluoromethylated tetrazoles, imidazoles, and 1,2,3‐triazoles by using sodium azide, activated methylene isocyanides, and diazo compounds as dipoles.