Stereospecific Synthesis of Highly Substituted Piperazines via a One-Pot Three Component Ring-Opening Cyclization from N-activated Aziridines, Anilines and Propargyl Carbonates.

A simple and efficient one-pot three-component synthetic route to highly substituted and functionalizable piperazines in high yields with excellent stereoselectivity (de, ee >99%) is reported. The S(N)2-type ring-opening of N-activated aziridines by anilines followed by Pd-catalyzed annulation with propargyl carbonates gives rise to the final piperazine products.