ChemInform Abstract: Photoinduced Electron Transfer Carbon-Carbon Bond Cleavage of Radical Cations of Carbonyl Compounds in Solution. 2,4,6-Triphenylpyrylium Salt-Sensitized Oxygenation of Aralkyl Ketones and Aldehydes.

Abstract

Photosensitized electron transfer oxygenation of several aralkyl ketones and aldehydes such as 1,2,2-triphenylethanone and diphenyl- and triphenylethanal has been carried out with 2,4,6-triphenylpyrylium tetrafluoroborate (TPP + BF 4 - ) in dichloromethane. The carbonyl compounds underwent C-C bond cleavage through they cation radicals, generated via electron transfer to the excited singlet state of the pyrylium salt. For example, diphenylethanal afforded benzophenone in 80% yield