201045-70-7Relevant academic research and scientific papers
A new palladium-catalyzed intramolecular allylation to pyrrolidin-2- ones
Giambastiani,Pacini,Porcelloni,Poli
, p. 804 - 807 (2007/10/03)
A novel palladium(0)-catalyzed cyclization to 3,4-disubstituted pyrrolidin-2-ones has been developed. The new approach relies upon the concomitant generation of stabilized acetamide enolate anions and of a π- allyl-palladium appendage, properly tethered by a nitrogen atom. Reaction conditions have been optimized for the methoxycarbonyl-stabilized model reaction [(Z)-2 → 3] and then applied to other substrates. A broad range of acetamide anion stabilizers was shown to allow the desired intramolecular C- C bond formation (MeO2C, MeCO, NC, (EtO)2PO, PhSO2). The cyclizations gave exclusively 5-exo-trig ring closure, thereby affording γ-lactams. All the cyclizations gave the corresponding 3,4-disubstituted pyrrolidin-2-ones with total diastereoselection. Complete trans preference was unequivocally demonstrated for the model reaction via a NOESY experiment.
