title: Chiral induction at octahedral Ru(II) via the disassembly of diruthenium(II,III) tetracarboxylates using a variety of chiral diphosphine ligands.
abstract: Achiral [Ru2(μ-O2CR)4(MeOH)2](PF6) (R = CH3 or C6H5) reacts with the chiral diphosphines R,R- and S,S-Chiraphos (two chiral centers on ligand between the coordinating P atoms) and R-Prophos (one chiral center on ligand between the coordinating P atoms) leading to a disassembly of the paddlewheel core and the highly diastereoselective production of Λ-[Ru(η(2)-O2CC6H5)(η(2)-R,R-Chiraphos)2](PF6) (Λ-R,R-III), Δ-[Ru(η(2)-O2CC6H5)(η(2)-S,S-Chiraphos)2](PF6) (Δ-S,S-III) (the R = CH3 complexes of Chiraphos were reported in a earlier communication in this journal), and Λ-[Ru(η(2)-O2CCH3)(η(2)-R-Prophos)2](PF6) (Λ-R,R-VI), respectively, in high yield and purity. Reactions of the same starting material with R,R- and S,S-o-tolyl-Dipamp (chiral centers are the coordinating P-atoms) lead to an inversion in the chirality-at-metal producing Λ-[Ru(η(2)-O2CC6H5)(η(2)-S,S-o-tolyl-Dipamp)2](PF6) (Λ-S,S-IV), Δ-[Ru(η(2)-O2CC6H5)(η(2)-R,R-o-tolyl-Dipamp)2](PF6) (Δ-R,R-IV), Λ-[Ru(η(2)-O2CCH3)(η(2)-S,S-o-tolyl-Dipamp)2](PF6) (Λ-S,S-V), and Δ-[Ru(η(2)-O2CCH3)(η(2)-R,R-o-tolyl-Dipamp)2](PF6) (Δ-R,R-V). X-ray crystallography of all but Λ-S,S-V and Δ-R,R-V and solid-state circular dichroism (CD) show that only the indicated diastereomers are present in the solid-state. Solution CD measurements and (31)P NMR also indicate their predominance in solution.
authors.affiliation: Department of Chemistry, St. Francis Xavier University , P.O. Box 5000, Antigonish, Nova Scotia, B2G 2W5, Canada.
authors.forename: Brandon R
authors.initials: BR
authors.lastname: Groves
authors.forename: D Ian
authors.initials: DI
authors.lastname: Arbuckle
authors.forename: Ernest
authors.initials: E
authors.lastname: Essoun
authors.forename: Travis L
authors.initials: TL
authors.lastname: Lundrigan
authors.forename: Ruiyao
authors.initials: R
authors.lastname: Wang
authors.forename: Manuel A S
authors.initials: MA
authors.lastname: Aquino