PHOTOCHEMISTRY AND PHOTOPHYSICS OF AROMATIC SULFOXIDES .3. ALPHA-CLEAVAGE AND THE ROLE OF THE SULFENIC ESTER

摘要

The photochemistry of aryl benzyl sulfoxides is described. The initial event is homolytic cleavage to form a singlet sulfinyl/benzyl radical pair. This radical pair partitions between reversion to starting material with at least partial racemization and closure to form a sulfenic ester. With acetone sensitization, the primary radical pair also undergoes quite significant escape, leading to formation of diphenylethane and aryl arenethiosulfonates. Secondary photolysis of the sulfenic ester leads exclusively to S-O homolysis, yielding the radical pair from which isolated products are derived. Quantum yields and other mechanistic observations are discussed. [References: 49]