Complexes with ligands of optically active sugar, process for their preparation and uses.

The invention relates to compounds of formula (I) and (Ia) wherein R1 represents a transferable group A carbonyl compounds or imine, eg Alkyl, allyl, vinyl or the remainder of an enol OR A enamine, R2 is, eg Cyclopentadienyl, R3 is the residue of a sugar or sugar derivative, optically active, ME IS IT, Zr or Hf, X = 0, 1 or 2 and y = 0, 1, 2 or 3, M + represents Li +, Na +, K + , MGY +, ZNY +, CDY +, HGY +, + O GUINEA PIG quaternary ammonium Y being a halogen. These compounds are suitable as reactants CHIRAL COMPOUNDS FOR GROUPS aldehyde, ketone and / or groups IMINO N-Substituted.