... g ... with C−Y bond formation and allylic rearrangement (demonstrated for X = Y: ArSO 2 N═S═O, SO 2 , SeO 2 , CO 2 , N 2 , H ... involves formation of reactive intermediates in which the H-transfer might not be the rate determining step (observed for X = Y: 1 O 2 , R′CON═NCOR ...