Radical rearrangement of N-sulfonyl-N-aryl propynamides: proceeding with homolytic N–SO₂ bond cleavage and 6-endo-dig cyclization toward 3-sulfonyl-2(1H)-quinolinones

A di-tert-butyl peroxide-promoted radical rearrangement of N-sulfonyl-N-aryl propynamides has been developed. This procedure proceeds with sequential homolytic N–SO₂ bond cleavage and 6-endo-dig radical cyclization to access a variety of 2-sulfonyl-3-aryl-2(1H)-quinolinones with high atom economy. The cross experiment confirmed the involvement of an intermolecular rearrangement, which was triggered by the thermo-induced homolytic cleavage of the N–SO₂ bond.