An efficient synthetic approach for N-C bond formation from (S)-amino acids: an easy access to cis-2,5disubstituted chiral piperazines

An efficient synthetic strategy is described for the construction of amino acids derived enantiomerically pure cis-2,5-disubstituted chiral piperazines. Cu-catalyzed spontaneous regioselective ring opening and ring closing of non-activated N-tosyl aziridines as well as Pd-mediated N-C bond formation from N-tosyl halogenated amino-derivatives are the key steps for accessing disubstituted piperazines.