Photoinduced electron transfer of benzyl phenyl sulfides promoted by 9,10-dicyanoanthracene

The photoinduced oxidation of benzyl phenyl sulfides 1-3 has been investigated in MeCN using 9,10-dicyanoanthracene as sensitizer in the presence of O-2. In this reaction a sulfide radical cation is formed, which undergoes one or more of the three main reaction pathways opened to these species: C-S bond cleavage, C-H bond cleavage and S-oxidation. The former route (leading to benzylic products) was observed with all the substrates investigated, whereas the second (leading to benzaldehydes) operates only with 1 and 2. Formation of sulfoxides was found solely in the photooxidation of 1. The influence of substrate structures on the relative contribution of the three pathways as well as the role of O-2(.) in this respect are discusse