Photodesulfonylation of indoles initiated by electron transfer from triethylamine

N-Sulfonyl indoles can be easily deprotected by a photoinduced electron transfer reaction with triethylamine. By using an equivalent amount of n-Bu3SnH in the photolysis medium, it is possible to suppress the competitive photo-Fries like rearrangement by scavenging the phenylsulfonyl radical.