Catalytic Aerobic Photooxidation of Phosphines using Four-coordinated Organoboron Compounds as Photocatalysts

A photooxidation approach to the conversion of phosphines into the corresponding phosphine oxides is reported. By taking advantage of O-2 in the air as an oxidant and oxygen source, phosphineoxides were obtained efficiently in moderate to excellent yields. A four-coordinated organoboron compound was used as the photocatalyst to activate O(2 )to its singlet state. This photooxidation method features mild reaction conditions, broad functional-group tolerance, and a wide substrate scope.