Metal complexes of biologically important ligands .86. Organometallic complexes of ruthenium(II), rhodium(III), iridium(III), and gold(I) with cinchona alkaloids

The following chiral organometallic complexes of the cinchona alkaloids quinine (L(1)), cinchonidine (L(2)), quinidine (L(3)), cinchonine (L(4)) were prepared: [(eta(5)-C5H5)(Ph(3)P) (OC)Ru(L)]BF4 (1: L=L(1); 2: L=L(2); 3: L=L(3)), ClAuL(1) (4), [(eta(5)-C(5)Me(5))(Cl-2)Ir(L)] (5: L=L(1); 6: L=L(2); 7: L=L(4)), [(eta(5)-C(5)Me(5))(Cl-2)Rh(L(2))] (8), [(eta(6)-p-cymene)(Cl-2)Ru(L)] (9: L=L(1); 10: L=L(2); 11: L=L(4)). In all complexes the tertiary nitrogen atom of the cinchona alkaloids is bound to the metal. Complexes 5-11 are formed as mixtures of isomers. Elimination of HCl from 10 and 11 gives the neutral N,O-chelate complexes (eta(6)-p-cymene) (Cl)Ru(L(2) - H+) (13) and (eta(6)-p-cymene)(Cl)Ru(L(4) - H+) (14) which were structurally characterized by X-ray diffraction.