Metal complexes with biologically important ligands, 127. Half-sandwich complexes of ruthenium, rhodium and iridium as well as phosphane-bearing palladium and platinum(III) complexes with Schiff bases for alpha-amino acid anions and aldehydes

Reactions of the anions (L) of Schiff bases from S-alpha -amino acids and c innamic aldehyde or 4-methoxy or 2,4-dimethoxy benzaldehyde with chloro-bri dged compounds (R3P)(Cl)M(mu -Cl)(2) M(Cl)(PR3) (M = Pd, Pt), (p-cymene)(Cl )Ru(mu -Cl)(2)Ru(Cl)(p-cymene) and (Cp*)(Cl)M(mu -Cl)(2)M(Cl)(Cp*) (M = Rh, IR) give the (N,O) chelate complexes cis/trans-(R3P)(Cl)M(L). (p-cymene)(C l)RuL and (Cp*)(Cl)M(L) (M = Rh. Ir). The complexes (Cp*)(CL)M[O2CCH(CHMe2) N=CH-CH=CHPh] (M = Rh, Ir) with a chiral metal atom are formed with a high diastereoisomeric excess (9/1). The structures of (p-cymene)(Cl)Ir[O2CCH(CH -Me-2)N=CH-CH=CHPh) (7), cis(P,N)-(Bu-n(3))(Cl)Pt[O2CCH(Me)-N=CH-C6H4OMe] ( 19), (Cp*)(Cl)Rh[O2CCH(Me)N=CH-C6H4OMe] (22) and of (p-cymene)(Cl)Ru[O2CCH( Me)N=CHC6H3(OMe)(2)] (26) were determined by X-ray diffraction. (C) 2001 El sevier Science B.V. All rights reserved.