Reactive Oxygen Species (ROS)-vs Peroxyl-Mediated Photosensitized Oxidation of Triphenylphosphine: A Comparative Study

J Org Chem. 2016 Dec 2;81(23):11678-11685. doi: 10.1021/acs.joc.6b02088. Epub 2016 Nov 15.

Abstract

The oxidation of triphenylphosphine in the presence of various photocatalytic systems (dicyanoanthracene/biphenyl, N-methylquinolinium, triphenylpyrylium, and thiatriphenylpyrylium tetrafluoroborate) was investigated by means of both steady state and laser flash photolysis experiments. The effect of different additives (including 1,4-benzoquinone, diphenylsulfoxide, tetramethylethylene, and sodium azide) on the photosensitized oxidation was investigated in order to fully characterize the involved intermediates. Photoinduced electron transfer and final regeneration of the catalyst occur when dicyanoanthracene and N-methylquinolinium are used, while in cage oxygen transfer to the photoexcited (thio)pyrylium derivatives have been characterized in the last two cases.