Copper(I) halide mediated tandem 1,4-aryl migration-oxidative amidyl radical cyclisation of bromosulfonamides

Reaction of N-butyl-N-(2-bromo-2-methylpropionyl)-arylsulfonamides with CuBr/tripyridylamine leads to amidyl radicals via 1,4-aryl migration with concomitant loss of SO2, which can further undergo cyclisation to oxindoles or reduction to amides with the ratio dependent upon the temperature and solvent utilised.