Cycloaddition of Diphenylcyclopropenone with Carboximidate, Carboximidamide, and Carboximidothioate

Article abstract of DOI:10.1246/bcsj.56.3849

The reaction of diphenylcyclopropenone with R¹N=C(R²)X (2) (R¹, R²=alkyl, aryl, X=MeO, EtO, MeS, or Me2N) gave 2-pyrrolin-4-one (3) in good yield.The less reactive carboximidothioate (2, R¹=4-MeC6H4, R²=Ph, X=MeS) yielded isomeric 3-pyrrolin-2-one together with 3.