METAL-COMPLEXES OF BIOLOGICALLY IMPORTANT LIGANDS .78. SYNTHESIS OF PALLADIUM COMPLEXES OF FERROCENYL-SUBSTITUTED AMINO-ACID DERIVATIVES

Schiff bases from ferrocene aldehyde and alpha-amino acidates react with PdCl2 or Na2PdCl4 to give N,O-chelate complexes (2a-e, 3). The related N-ferrocenylmethylen-alpha-amino acid esters give, with Pd(OAc)(2), cyclopalladated acetate-bridged complexes (4a,b). N,O-chelate complexes (5-7) are obtained from Na2PdCl4 with N-ferrocenylmethyl prolinate and-alaninate as well as with N,N-dibenzyl glycinate. The ethyl ester of N,N-dibenzylglycine and Pd(OAc)(2) form the cyclopalladated acetate-bridged complex 8, while the ester of N-monobenzylglycine and Na2PdCl4 affords trans-PdCl2(L)(2) with a monodentate N-coordinated ligand. The structures of 2a, 4a, 5, 7, and 9 were determined by X-ray diffraction.