Asymmetric Synthesis of Densely Functionalized Pyrazolidines and 1,3-Diamines

A versatile and straightforward access to polysubstituted 1,3-diamines with good control of relative and absolute configurations is described. The key steps involve a diastereoselective 1,3-dipolar cycloaddition of a chiral non-racemic azomethine imine ylide and a chemoselective electroreduction of densely functionalized pyrazolidines intermediates.