ADDITION OF DIETHYLZINC TO ARYL ALDEHYDES CATALYZED BY )-N,NI-BIS[BENZYL]-1,3-DIPHENYL-1,3-PROPANEDIAMINE AND ITS DILITHIUM SALT - A MECHANISTIC RATIONALE INVESTIGATION

N,N1-bis-benzyl substituted 1,3-diamine 1a, synthesized in high optica l purity, and the corresponding dilithium salt 1b are used, for the fi rst time, as chiral catalysts in the addition of ZnEt2 to aromatic ald ehydes. Both 1a and 1b are able to promote the reaction but the produc ts obtained exhibited low enantiomeric excesses. By H-1 NMR and UV-CD investigation, experimental evidences about the structure of some reac tion intermediates have been gained: reaction pathway consistent with spectroscopic data, chemical and stereochemical results could be postu lated.