An efficient and facile synthesis of divergent C-3/C-5 bis-functionalized 2-oxindoles from 5-formyl-Morita-Baylis-Hillman adducts of oxindole

An efficient and facile synthesis of divergent C-3/C-5 bis-functionalized 2-oxindole derivatives has been achieved from 3,5-bis-Morita-Baylis-Hillman (MBH) adducts of oxindole via nucleophilic substitution reaction for the first time. Wider scope of substrate and rate acceleration has been observed in second MBH reaction under typical reaction condition. The synthetic usefulness of bi-functionalized bis-allyl derivative has been demonstrated by the synthesis of potent bis-pyrazole via [3 + 2]-annulation strategy.