Organocatalytic α-amination–allylation-RCM strategy: enantioselective synthesis of cyclic hydrazines

A highly enantioselective method for the synthesis of cyclic hydrazines by using organocatalytic α-amination–allylation-RCM strategy is described. Proline-catalyzed α-amination of aldehydes followed by indium-mediated one-pot allylation of the crude α-hydrazino aldehydes produces 1,2-aminoalcohols in high enantio- and diastereoselectivities. The 1,2-aminoalcohols are further converted into cyclic hydrazines by using ring-closing metathesis (RCM) reaction.