Tandem reaction of propargylic alcohol, sulfonamide, and N-iodosuccinimide: synthesis of N-(2-iodoinden-1-yl)arenesulfonamide.

An efficient and straightforward strategy for the synthesis of N-(2-haloinden-1-yl)arenesulfonamides from propargylic alcohols and sulfonamides is described. Allenesulfonamide is postulated to be the key intermediate for this tandem transformation.