Ru-Catalyzed Hydrogen Atom Transfer/C-F Bond Cleavage of Difluoroalkyl Diazos with Hantzsch Ester via a Photocatalytic Radical Process.

A Ru-catalyzed reaction of difluoroalkyl diazo compounds with Hantzsch ester under visible light to achieve the formation of α-fluorovinylphosphonates via a radical process has been developed. Mechanistic experiments and density functional theory calculations reveal that the generation of a carbon radical is directly through the hydrogen atom transfer (HAT) by Hantzsch ester. This system represents the first example of generation of carbon radicals from diazo compounds via Hantzsch-ester-assisted HAT and also demonstrates a new radical-involved pathway for the difluoroalkyl diazo compounds.