Difluorocarbene-Enabled Trifluoromethylation and Cyclization for the Synthesis of 3-(Trifluoromethyl)-4 H-pyrans

Org Lett. 2024 Oct 11;26(40):8589-8593. doi: 10.1021/acs.orglett.4c03266. Epub 2024 Sep 27.

Abstract

A three-component annulation reaction and trifluoromethylation for the construction of 3-(trifluoromethyl)-4H-pyrans using β-CF3-1,3-enynes, BrCF2CO2Et, and sulfoxonium ylides as readily available substrates has been developed. This metal-free process involves two C-F bond cleavages of β-CF3-1,3-enynes and a CF3 group generated in situ from BrCF2CO2Et. This method is applicable to the late-stage modification of pharmaceutically active molecules.