A series of tetrahydroisoquinoline derivatives were prepared via a three-component aza-Diels-Alder reaction. Keys to the success of this reaction are a) the utilization of sultines as masked o-quinodimethanes, b) the facile, in situ generation of imine dienophiles, and c) the presence of Cu(OTf)2 as a Lewis acid to promote the desired reactivity.
Reported herein is the development of a normal electron-demand, three-component aza-Diels-Alder reaction between sultines, aldehydes, and amines. In the presence of Cu(OTf)2 as a Lewis acid catalyst, the use of sultines as o-quinodimethane precursors in conjunction with the in situ generation of imines enables the facile preparation of various polysubstituted tetrahydro-isoquinoline derivatives from readily available substrates. The synthetic utility of these products was further explored through a number of product transformations, including the syntheses of tricyclic N-heterocycles.Zum Volltext