Diastereoselective formation of metallamacrocyclic (arene)Ru(II) and CpRh(III) complexes.
The reaction of [(arene)RuCl(2)](2) (arene = cymene, 1,3,5-C(6)H(3)Me(3)) and [CpRhCl(2)](2) half-sandwich complexes with tridentate heterocyclic ligands in the presence of base has been investigated. In all cases, the chloro-ligands were substituted to give metallacyclic products with ring sizes between 4 and 18 atoms. The cyclization occurs in a highly diastereoselective fashion with chiral recognition between the different metal fragments. The complexes were comprehensively characterized by elemental analysis, NMR spectroscopy, and single crystal X-ray crystallography. For 2-hydroxy-nicotinic acid and 2-amino-nicotinic acid, dinuclear structures were obtained (15-17) whereas for 2,3-dihydroxyquinoline, 2,3-dihydroxyquinoxaline, and 6-methyl-2,3-phenazinediol, trimeric assemblies were found (19-22), and for 4-imidazolecarboxylic acid, a tetrameric assembly (18) was found.
Institut de Chimie Moléculaire et Biologique, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Suisse.
Marie-Line
ML
Lehaire
Rosario
R
Scopelliti
Lorenz
L
Herdeis
Kurt
K
Polborn
Peter
P
Mayer
Kay
K
Severin