Base-catalyzed cascade synthesis of 2,3-dihydrofuro[2,3-b]pyridines and 2,3-dihydro-1H-pyrrolo[2,3-b]pyridines from N-propargylic β-enaminones

A novel protocol to prepare multi-substituted dihydrofuropyridine and dihydropyrrolopyridine derivatives from KOH-catalyzed reactions between readily available N-propargylic β-enaminones and arylaldehydes or N-sulfonyl imines has been developed in moderate to good yields.