Highly Diastereoselective DABCO-Catalyzed [3+3]-Cycloaddition of 1,4-Dithiane-2,5-diol with Azomethine Imines

An effective diastereoselective [3 + 3] cycloaddition of 1,4-dithiane-2,5-diol with azomethine imines catalyzed by DABCO is described. A variety of highly functionalized six-membered dinitrogen-fused heterocycles can be obtained in good yield with excellent diastereoselectivity, which was controlled by anomeric effect.