Highly diastereoselective preparation of ruthenium bis(diimine) sulfoxide complexes: New concept in the preparation of optically active octahedral ruthenium complexes

Citation
F. Pezet et al., Highly diastereoselective preparation of ruthenium bis(diimine) sulfoxide complexes: New concept in the preparation of optically active octahedral ruthenium complexes, ORGANOMETAL, 19(20), 2000, pp. 4008-4015
Citations number
48
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
ORGANOMETALLICS
ISSN journal
0276-7333 → ACNP
Volume
19
Issue
20
Year of publication
2000
Pages
4008 - 4015
Database
ISI
SICI code
0276-7333(20001002)19:20<4008:HDPORB>2.0.ZU;2-#
Abstract
Microwave irradiation of racemic cis-[Ru(bpy)(2)(Cl)(2)] (bpy = 2,2'-bipyri dine) or racemic cis[Ru(phen)(2)(Cl)(2)] (phen phenanthroline) with either (R)-(+)- or (S)-(-)-methyl p-tolyl sulfoxide yielded the ruthenium bis(diim ine) sulfoxide complexes with a high level of asymmetric induction (13-76% de). Stereochemistry at the metal center for the major isomer was determine d by X-ray study of [Ru(bpy)(2)(dmbpy)]. 2PF(6), obtained by reaction of co mplex 3 with 4,4'-dimethyl-2,2'-bipyridine and confirmed by X-ray study of the complex 7. The absolute configuration at the metal center for the minor isomer was established by X-ray study of the minor isomer derived from the reaction of cis-[Ru(bpy)(2)(Cl)(2)] with (S)-(-)-methyl p-tolyl sulfoxide. Structural analysis of Delta-7 (major isomer) revealed the presence of two intramolecular interactions, oxygen-hydrogen interaction and pi-pi stackin g of the pyridyl-tolyl rings, while the structural analysis of Delta-5 (min or isomer) showed only the presence of the oxygen-hydrogen interaction. The importance of these interactions in this transformation was confirmed by t he reaction of cis-[Ru(2,9-dimethyl-1,10-phenanthroline)(2)Cl-2]with (R)-()-methyl p-tolyl sulfoxide, which gave, in acetonitrile, the complex cis-[R u(2,9-dimethyl-1,10-phenanthroline)(2)(CH3CN)(2)]. 2PF(6), 10. Oxygen-hydro gen and pi-pi interactions are used to explain both the reactivity of cis-[ Ru(diimine)(2)Cl-2] with the sulfoxide and the stability of the major isome r when enantiomerically pure sulfoxide was used.