| Abstract
| - A new concept in the synthesis of optically active octahedral ruthenium complexes was realized for the first time when cis- or trans-Ru(dmbpy)2Cl2 (cis- or trans-6) (dmbpy = 4,4‘-dimethyl-2,2‘-bipyridine) was diastereoselectively reacted with either (R)-(+)- or (S)-(−)-methyl p-tolyl sulfoxide (2 or 3) complex cis-Δ-[Ru(dmbpy)2(2)Cl]Cl (7) (59.5% de) or cis-Λ-[Ru(dmbpy)2(3)Cl]Cl (8) (57.2% de), respectively. In these, and other reactions described, the diastereoselectivity observed is governed solely by the chirality of the sulfoxide nucleophile.
- A new concept in the synthesis of optically active octahedral ruthenium complexes was realized for the first timewhen cis- or trans-Ru(bpy)2Cl, (cis- or trans-1) was reacted with either (R)-(+)- or (S)-(−)-methyl p-tolyl sulfoxide(2 or 3); this novel asymmetric synthesis leads to the diastereoselective formation of the ruthenium bis(bipyridine)complex cis-Δ-[Ru(bpy)2(2)Cl]Cl (4) (49.6% de) or cis-Λ-[Ru(bpy)2(3)Cl]Cl (5) (48.4% de), respectively. cis- ortrans-Ru(dmbpy)2Cl2 (cis- or trans-6) (dmbpy = 4,4‘-dimethyl-2,2‘-bipyridine) also reacts with 2 or 3, leading tothe diastereoselective formation of cis-Δ-[Ru(dmbpy)2(2)Cl]Cl (7) (59.5% de) or cis-Λ-[Ru(dmbpy)2(3)Cl]Cl (8)(57.2% de), respectively. The diastereoselectivity of these reactions is governed solely by the chirality of thesulfoxide nucleophile. This represents the first process by which a σ-bonded ligand occupying only a singlecoordination site has had such an important influence on the stereochemical outcome of a ruthenium bis(bipyridine)complex formation. These novel complexes were fully characterized by elemental analysis and IR, UV/vis, and1H, 13C, and 2D NMR spectroscopy. An investigation into the chiroptical properties of these novel rutheniumbis(bipyridine) sulfoxide complexes has been carried out, and circular dichroism spectra are used to assign absolutestereochemistry.
|
