Silver/palladium relay catalyzed 1,3-dipole annulation/allylation reactions to access fully substituted allyl imidazolidines

A silver/palladium relay catalyzed 1,3-dipole annulation/allylation reaction of iminoesters and Baylis-Hillman acetates for the construction of fully substituted allyl imidazolidines is reported. The reaction of both iminoesters and Baylis-Hillman acetates affords the fully substituted allyl imidazolidines in high yields and regioselectivities. The three component reaction is triggered by silver-catalyzed 1,3-dipole annulation, followed by the sequential palladium catalyzed allylation. Mechanistic studies reveal that the dual catalytic system plays a key role in the reaction. The developed methodology provides straightforward access to allyl imidazolidines under simple reaction conditions.