Bromo-catalyzed photo esterification of benzylsilanes with alcohols under aerobic conditions

A photoinduced esterification reaction has been developed. In this reaction, benzylsilane shows very nice reactivity and selectivity, affording the corresponding esters as the only products. Under photo irradiation, the highly active bromo radical can be generated from the pre-catalyst CBr4, which would promote the initial CSi bond cleavage of benzylsilane via single electron transfer and the final transformation of acetal into ester via proton transfer. The existence of oxygen can not only oxidize the in situ generated benzyl radical into aldehyde intermediate, but also assist to regenerate bromo radical from bromine anion.