In this letter we highlight our results on the electrophilic sulfonylation of indoles with sulfonyl chlorides using a catalytic amount of indium bromide. Thus treatment of indole 1 (R=H) with phenylsulfonyl chloride 2 (Ar=Ph) in the presence of 10% InBr 3 in 1,2-dichloroethane afforded 3-phenylsulfonyl-1H-indole 3b in 87% yield (Scheme 1). ... A variety of indoles reacted smoothly with sulfonyl chlorides under similar conditions to give the corresponding 3-arylsulfonyl ...