Regio- and diastereoselective cycloaddition of stable cyclic azomethine imines to N-arylitaconimides

Abstract

1,3-Dipolar cycloaddition of stable N,N′- and C,N-cyclic azomethine imines based respectively on pyrazolidin-3-one and 3,4-dihydroisoquinoline to N-arylitaconimides proceeds strictly regioselectively resulting in spiro-joint heterocycles in good yields. The regioselectivity of the addition of N,N′-cyclic azomethine imines is reversed with respect to that of C,N-cyclic azomethine imines. The diastereoselectivity of the cycloaddition depends apparently on the substituents at the central nitrogen atom in the azomethine imine fragment.