METAL-COMPLEXES OF BIOLOGICALLY IMPORTANT LIGANDS, 101 - OXIDATIVE ADDITION OF ALPHA-BROMOGLYCINE TO PALLADIUM(0) AND PLATINUM(0) COMPLEXES- ALPHA-METALATED AMINO-ACIDS AS MODELS FOR INTERMEDIATES IN THE METAL-CATALYZED HYDROGENATION OF DEHYDROAMINO ACIDS

Oxidative addition of methyl N-benzoyl-2-bromoglycinate to bis(dibenzy lideneacetone)palladium, in the presence of 2,2'-bipyridyl, and to (Ph 3P)(2)Pt(eta(2)-C2H4) gives the alpha-metallated glycine esters 1a and 2a. Abstraction of bromide from 1a, 2a,using AgSbF6 or AgBF4, affords the cationic C,O-chelate complexes [(bpy)Pd-CH(CO2Me)NHC(Ph)O](+) (1b ,c) and [(Ph3P)(2)Pt-CH(CO2Me)NHC(Ph)O](+) (2b), respectively, fea tur ing coordination of the amide O atom. The complexes 1b and 2b have bee n characterized by X-ray diffraction.