Efficient copper-catalyzed direct intramolecular aminotrifluoromethylation of unactivated alkenes with diverse nitrogen-based nucleophiles

Abstract

A mild, convenient, and step-economical intramolecular aminotrifluoromethylation of unactivated alkenes with a variety of electronically distinct, nitrogen-based nucleophiles in the presence of a simple copper salt catalyst, in the absence of extra ligands, is described. Many different nitrogen-based nucleophiles (e.g., basic primary aliphatic and aromatic amines, sulfonamides, carbamates, and ureas) can be employed in this new aminotrifluoromethylation reaction. The aminotrifluoromethylation process allows straightforward access to diversely substituted CF3-containing pyrrolidines or indolines, in good to excellent yields, through a direct difunctionalization strategy from the respective acyclic starting materials. Mechanistic studies were conducted and a plausible mechanism was proposed.

Keywords: alkenes; aminotrifluoromethylation; copper; nitrogen heterocycles; nitrogen-based nucleophiles.