Reaction of diimines and azines with diphenylcyclopropenone

1-Cyclohexyl-2-cyclohexylaminomethylene-4,5-diphenyl-1,2-dihydropyrrol-3-one 4a and 1-aryl-2-arylamino-methylene-4,5-diphenyl-1,2-dihydropyrrol-3-ones 4b, c as the E-form are synthesized by the reaction between N,N'-dicyclohexylethane-1,2-diylidenediamine 2a and N,N'-diarylethane-1,2-diylidenediamines 2b, c with diphenylcyclopropenone 1 through a formal [2 + 3] cycloaddition reaction. The structure assignment of 4a is confirmed on the basis of an X-ray crystal-structure determination. Similarly, diaryl azines 8a-c react with 1 through a formal [2 + 3] cycloaddition reaction to give the non-isolable product Delta(4)-pyrrolin-3-ones 10a-c which undergo oxidative rearrangement to afford ultimately the indenone derivatives 9a-c.