Denitrogenative Hydrotrifluoromethylation of Benzaldehyde Hydrazones: Synthesis of (2,2,2-Trifluoroethyl)arenes

Chemistry. 2019 Aug 27;25(48):11240-11245. doi: 10.1002/chem.201902818. Epub 2019 Aug 7.

Abstract

Reacting hydrazones of arylaldehydes with Togni's CF3 -benziodoxolone reagent, in the presence of potassium hydroxide and cesium fluoride, induces a denitrogenative hydrotrifluoromethylation event to produce (2,2,2-trifluoroethyl)arenes. This novel reaction was tolerant to many electronically-diverse functional groups and substitution patterns, as well as naphthyl- and heteroaryl-derived substrates. Advantages of this process include the easy access to hydrazone precursors on a large scale, speed and operational simplicity, and being transition metal-free.

Keywords: Wolff-Kishner; fluorine; hydrazones; hypervalent iodine; trifluoromethylation.