One-pot domino reactions for synthesis of heterocyclic[3.3.3]propellanes and spiro[cyclopenta[b]pyridine-4,2′-indenes]

An efficient synthetic procedure for the functionalized heterocyclic[3.3.3]propellanes was successfully developed by one-pot domino reaction of ninhydrin, malononitrile with 3-arylamino-2-cyclohexenones and their 5,5-dimethyl derivatives in the presence of triethylamine in ethanol at room temperature. On the other hand the similar one-pot reaction containing 3-arylamino-2-cyclopentenones resulted in the functionalized spiro[cyclopenta[b]pyridine-4,2′-indenes] in moderate yields.