N-Heterocyclic Carbene Catalyzed Enantioselective [3 + 2] Dearomatizing Annulation of Saturated Carboxylic Esters with N-Iminoisoquinolinium Ylides

摘要

The dearomatizing annulation reaction is a significant challenge in organic chemistry. The direct activation of α-carbons of simple saturated esters, as nucleophiles, is an important synthesis strategy. In the present study, we disclose [3 + 2] dearomatizing annulation reactions with direct activating α-carbons of saturated carboxylic esters and N -iminoisoquinolinium ylides, which possess highly enantioselective characteristics, catalyzed by N -heterocyclic carbenes (NHCs). The protocol achieves isoquinoline dearomatization and the construction of tricyclic chiral products under mild conditions with good yield, substrate tolerance, and diastereoselectivity as well as excellent enantioselectivity.