Reaction of Diphenylcyclopropenone with Primary and Secondary Enaminones. Synthetic and Mechanistic Implications

Article abstract of DOI:10.1021/jo01314a026

Diphenylcyclopropenone (1) reacts with the primary and secondary acyclic enaminones 6a-c in toluene at reflux to afford the 1,5-dihydro-2H-pyrrol-2-ones 7a-c in good yield.The reaction of the primary cyclic enaminone 13a produces a 1,5-dihydro-4H-pyrrol-4-one 14, while the secondary cyclic enaminone 13b yields a 2:1 product (16b) as the principal cycloadduct.Mechanisms are discussed.