METAL-COMPLEXES OF BIOLOGICALLY IMPORTANT LIGANDS .70. SYNTHESIS, STEREOCHEMISTRY AND REACTIONS OF RUTHENIUM(II) AND OSMIUM(II) COMPLEXES WITH ALPHA-AMINO CARBOXYLATES

The reactions of MHCI(CO)(PPh3)3 with salts of alpha-amino acids give the hydrido-N,O-chelate complexes MH(CO)(NH2CHR-COO)(PPh3)2 (1a-g; M = Ru, Os). Complexes la-c can alternatively be prepared by oxidative addition of the appropriate alpha-amino acid to Ru(CO)3(PPh3)2. The crystal structure of lb has been determined by an X-ray structural analysis. The leucinato compound Ic is an effective catalyst or the decomposition of formic acid. In contrast, reactions of RuHCl(CO)(PPh3)3 with alpha-amino acids afford the chloro-N,O-chelate complexes RuCl(CO)(NH2CHRCOO)(PPh3)2 2a-h. The decomposition reactions of 2c, 2g and 2h have been investigated.