Enantioselective H-bond-directed vinylogous iminium ion strategy for the functionalization of vinyl-substituted heteroaryl aldehydes

In this work the first H-bond-directed vinylogous iminium ion strategy has been developed as a convenient strategy for the gamma,delta-functionalization of vinyl-substituted heteroaromatic aldehydes. Their reaction with alpha-mercaptoketones proceeds in a cascade manner involving 1,6-addition followed by intramolecular aldol reaction. Excellent stereoselectivities have been obtained as a result of the H-bond interactions controlling the outcome of the cyclization step. The application of the strategy for the synthesis of tricyclic compounds bearing furan, tetrahydrothiophene and dihydropyran moieties has also been demonstrated.

Automated summary

In this work, a novel H-bond-directed vinylogous iminium ion strategy has been developed for the gamma, delta-functionalization of vinyl-substituted heteroaromatic aldehydes. The strategy allows for the synthesis of tricyclic compounds with excellent stereoselectivity, demonstrating the potential applications in complex molecule synthesis.