Photoreduction of 1,1-diphenyl-2-haloethenes by metal hydrides

Article abstract of DOI:10.1016/S0040-4020(01)86510-8

The nature of the photochemical carbon - halogen bond cleavage in the presence of sodium borohydride or lithium aluminium hydride as reducing agents was studied when a halogen atom is bonded to the sp² hybridized carbon atom, which is a part of a vinyl system. Irradiation of 1,1-diphenyl-2-bromoethene, or 1,1-diphenyl-2-chloroethene, in the presence of the metal hydrides resulted in an increased formation of the photoreduced product 1,1-diphenylethene in comparison to reactions run in their absence. Conversion of the starting compound and the products distribution depended on the halogen atom bonded, the reducing agent, and the solvent used.