New chiral ferrocenylamine sulfide and selenide ligands: preparation, characterization and their palladium and platinum complexes as catalysts for selective hydrogenation

A series of new ferrocenylamine sulfides and selenides, (R,S)-(C₅H₃-1-CHMeNMe2-2-ER)Fe(C₅H₄ER), (E = S; R = Me, Ph, Bz, 4-tolyl and 4-chlorophenyl and E = Se; R = Ph and 4-chlorophenyl) have been prepared by the lithiation of (R)-N,N-dimethyl-1-ferrocenylethylamine, first in the presence of ether and then TMEDA followed by reaction with the appropriate disulfides or diselenides. These compounds react with (PhCN)₂MCl₂, M Pd, Pt to form new heterobimetallic complexes, (R,S)-(C₅H₄-ER)Fe(C₅H₃-1-CHMeNMe₂-2-ER)MCl₂, (E = S, Se; R = Me, Et, n-Pr, i-Pr [1], Ph, Bz, 4-tolyl and 4-chlorophenyl; M = Pd, Pt). The following techniques were used for characterization: ¹H and ¹³C NMR, IR, MS and elemental analysis. The possible structure for the bimetallic complexes is discussed. The palladium ferrocenyl complexes are effective catalysts for selective hydrogenation of dienes to monoenes under homogeneous conditions.