gem-Difluoroolefination of Amides

Chemistry. 2023 Dec 14;29(70):e202303144. doi: 10.1002/chem.202303144. Epub 2023 Oct 20.

Abstract

A metal-free one-pot process for the gem-difluoroolefination of amides is described. The reaction is based on interaction of generated in situ α-chloroiminium salts with difluorinated phosphorus ylide formed from difluorocarbene and triphenylphosphine. The olefination involves nucleophile-assisted dephosphorylation and proceeds within one hour at low temperature. The gem-difluoroenamines were used in further transformations leading to a variety of fluoroalkylated amines.

Keywords: difluorocarbene; enamines; fluorine; olefination; ylides.