402828-66-4Relevant articles and documents
Stoichiometric C-H Bond Cleavage Reaction in a Bis(carboxylato)ruthenium(II) Complex and Its Application to the Catalytic H-D Exchange Reaction of Carboxylic Acids
Hirano, Masafumi,Fujimoto, Ryo,Hatagami, Kohei,Komine, Nobuyuki,Komiya, Sanshiro
, p. 1101 - 1115 (2013)
A cationic complex [Ru{OC(O)CMe=CH2-κ2O,O'}(PMe3)4]+CH2=CMeCO2- (5a) and its related carboxylato complexes are newly prepared by the reaction of [cis-RuH2(PMe3)4] (4) with carboxylic acids in methanol in 76-100% yield. Complex 5a reversibly transforms to the neutral form [cis-Ru{OC(O)CMe=CH2-κ1O}2(PMe3)4] (2a) in nonpolar solvents. Complex 2a reversibly liberates a PMe3 group to give [Ru{OC(O)CMe=CH2-κ1O}{OC(O)CMe=CH2-κ2O,O'}(PMe3)3] (12a) from which a stereoselective C-H bond cleavage reaction occurs to give a ruthenalactone [Ru{OC(O)CMe=CH-κ2O,C}(PMe3)4] (1a) from the release of methacrylic acid. Complexes 2a and 5a also give 1a but the prior dissociation of a PMe3 is indispensable for the C-H bond cleavage reaction. Complex 1a establishes an equilibrium with 2a (or 5a) in solution. In this reaction, one coordinated carboxylato ligand is engaged in the C-H bond cleavage reaction as a proton acceptor, but neither the added carboxylato anion nor typical proton acceptors such as proton sponge assist the reaction. In [D4]MeOH, a catalytic stereospecific deuteration of carboxylic acids has been achieved by 4, in which the equilibrium between 5a and 1a plays a key role.
