Chiral nitrogen-stabilized Fischer carbene complexes: an efficient tool inthe stereocontrolled elaboration of additional stereogenic centers

The elaboration of the organic ligand of amino and hydrazino carbene comple xes of the Fischer type through the reactions of their anions with electrop hiles is a useful tool for achieving the stereoselective formation of new c arbon-carbon bonds. Anions of chiral carbene complexes substituted with a C -2 symmetry amine give stereoselective 1,4-Michael additions to nitroolefin s, thus achieving a new entry to beta-aryl-gamma-aminobutyric acid derivati ves, which are biologically important molecules. Moreover, two new and comp lementary protocols for the synthesis of alkyl hydrazino carbene complexes have been developed and the first reactions of their conjugated bases with alkyl halides and aldehydes are reported.