Iron(II)-Catalyzed Azidotrifluoromethylation of Olefins and N-Heterocycles for Expedient Vicinal Trifluoromethyl Amine Synthesis

ACS Catal. 2018 Jun 1;8(6):5032-5037. doi: 10.1021/acscatal.8b01253. Epub 2018 Apr 20.

Abstract

We report herein an iron-catalyzed azidotrifluoromethylation method for expedient vicinal trifluoromethyl primary-amine synthesis. This method is effective for a broad range of olefins and N-heterocycles, and it facilitates efficient synthesis of a wide variety of vicinal trifluoromethyl primary amines, including those that prove difficult to synthesize with existing approaches. Our preliminary mechanistic studies revealed that the catalyst-promoted azido-group transfer proceeds through a carbo-radical instead of a carbocation species. Characterization of an active iron catalyst through X-ray crystallographic studies suggests that in situ generated, structurally novel iron-azide complexes promote the oxidant activation and selective azido-group transfer.

Keywords: N-heterocycles; azides; iron catalysis; olefins; trifluoromethyl amines.