Dimerization of Lithiated Terminal Aziridines

Let's get together: Dimerization of enantiopure terminal aziridines by lithiation gives efficiently N-protected 2-ene-1,4-diamines with complete selectivity for the E olefin (see scheme). The usefulness of the method was demonstrated in a concise synthesis of (R,S,S,R)-2,5-diamino-1,6-diphenylhexane-3,4-diol, the core unit of many extremely potent HIV protease inhibitors and also asymmetric catalysts.