K. Osakada

Preparation and properties of hydride triphenyl-phosphine ruthenium complexes with 3-formyl (or acyl) propionate [RuH(ocochrchrcor′)(PPh3)3] (R H, CH3, C2H5; R H, CH3, C6H5) and with 2-formyl (or acyl) benzoate [RuH(o-OCCOC6H4COR′)(PPh3)3] (R′ H, CH3)

Abstract Reactions of Five-membered cyclic dicarboxylic anhydrides, such as phthalic anhydride and succinic anhydride, with RuH2(PPh3)3] and 3-formyl propionate [RuH(OCOCH2CH2CHO)(PPh3)3], via the Cue5f8O bond cleavage of the anhydrides. Similar reactions of methylsuccinic anhydride or ethylsuccinic anhydride with RuH2(PPh3)4 afford mixtures of the isomers [RuH(OCOCHRCH2CHO)(PPh3)3] and RuH(OCOCH2CHRCHO)(PPh3)3] (R ue5fb CH3 or C2H5), in ca. 3 to 1 molar ratio in each reaction. Complexes with 2-acyl benzoate or 3-acyl propionate ligands formulated as [RuH(o-OCOC6H4COCH3(PPH3)3] or [RuH(OCOCH2CH2COR/t)(PPh3)3](R/t ue5fb CH3, C6H5) are prepared from the reaction of corresponding 2-acyl benzoic or 3-acyl propionic acids with RuH2(PPh3)4. Upon contact with hydrogen at elevated pressure, or with hydrogen chloride or carbon monoxide at atmospheric pressure, these complexes release the corresponding γ-lactones, which are formed through the reduction of formyl or acyl groups in the carboxylate ligands followed by intramolecular condensations. Hydrogenation of 3-acyl propionic acids using ruthenium(II) complexes as catalyst gives γ-substituted γ-lactones in high yields.

Catalytic asymmetric hydrogenation of cyclic anhydrides using ruthenium (II) chiral phosphine complex

Abstract Optically active γ- and δ-lactones are obtained by the hydrogenation of five- and six-membered cyclic anhydrides using a Ru(II) complex with chiral phosphine ligand, DIOP, as a catalyst.

Catalytic regioselective dehydrogenation of unsymmetrical α,ω-diols using ruthenium complexes

Abstract Ruthenium complex catalyzed regioselective dehydrogenation of unsymmetrically substituted 1,4- and 1,5-diols in the presence of α,β-unsaturated ketone as a hydrogen acceptor and triethylamine gave β-substituted γ-lactones and γ-substituted δ-lactones as major products, respectively.