γ-Selective Vinylogous Aza-Morita–Baylis–Hillman Reaction with N-Carbamoylimines

Abstract

Vinylogous aza-Morita–Baylis–Hillman (aza-MBH) reactions of a vinylcyclopentenone with N-Boc imines provide the corresponding γ-adducts in high regioselectivity (10 examples). While the corresponding reactions with N-Ts imines give the α-adducts and γ-adducts depending on the catalyst, those with N-Boc imines proceed in a γ-selective manner, irrespective of the promoter. The nature of the protecting groups on the nitrogen of the aldimines is found to play a key role in the regiochemical course of vinylogous aza-MBH reactions.