Metal Complexes of Biologically Important Ligands, LXXXVI. 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: [(η 5 ‐C 5 H 5 )(Ph 3 P)(OC)‐Ru(L)]BF 4 ( 1 : L=L 1 ; 2 : L=L 2 ; 3 : L=L 3 ), ClAuL 1 ( 4 ), [(η 5 ‐C 5 Me 5 )(Cl 2 )Ir(L)] ( 5 : L=L 1 ; 6 : L=L 2 ; 7 : L=L 4 ), [(η 5 ‐C 5 Me 5 )(Cl 2 )Rh(L 2 )] ( 8 ), [(η 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 (η 6 ‐ p ‐cymene)(Cl)Ru(L 2 – H + ) ( 13 ) and (η 6 ‐ p ‐cymene)‐(Cl)Ru(L 4 – H + ) ( 14 ) which were structurally characterized by X‐ray diffraction.