Asymmetric cross-dimerization between methyl methacrylate and substituted alkene by Ru(0)-bicyclononadiene complex.

New Ru(0)-naphthalene complexes containing a bicyclononadiene ligand catalyze the linear cross-dimerization between methyl methacrylate and substituted alkenes by an oxidative coupling mechanism. The chiral (S,S)-2-methylbicyclo[3.3.1]nona-2,6-diene complex (S,S)-1b catalyzes asymmetric linear cross-dimerization between methyl methacrylate and 2,5-dihydrofuran to give the cross-dimer in 74% yield in 80% ee.

Reaction of an oxaruthenacycle with DMAD. Stoichiometric transformations of 2,6-xylenol to allylic phenols and benzopyrans via sp(3) C-H bond cleavage reaction.

Insertion of a dimethyl acetylenedicarboxylate (DMAD) into the Ru-C bond in a cycloruthenated complex Ru[OC(6)H(3)(2-CH(2))(6-Me)-kappa(2)O,C](PMe(3))(4) () has been achieved to give a seven-membered oxaruthenacycle Ru[OC(6)H(3){2-CH(2)C(CO(2)Me)[double bond, length as m-dash]C(CO(2)Me)}(6-Me)-kappa(2)O,C](PMe(3))(3) () in 47% yield. The molecular structure of by X-ray analysis shows an agostic interaction between the ruthenium and one of the benzylic methylene protons. Complex shows fluxional behaviour in solution and the variable temperature NMR studies suggest this fluxionality to be responsible for the turnstile rotation of three PMe(3) ligands and the rotation of the alpha-methoxycarbonyl group. Heating of a toluene solution of at 100 degrees C for 2 h results in the 1,3-H shift reaction in to give a kappa(1)O,eta(3)-C,C',C'' allylic complex Ru[OC(6)H(3){2-CHC(CO(2)Me)CH(CO(2)Me)}(6-Me)-kappa(1)O,eta(3)C,C',C''](PMe(3))(3) () (80-90%), whose molecular structure is revealed by X-ray analysis. Acidolyses of and give 2-[(Z)-2',3'-bis(methoxycarbonyl)allyl]-6-methylphenol () (88%) and 2-[(Z)-2',3'-bis(methoxycarbonyl)propenyl]-6-methylphenol () (47%), respectively, and iodolyses of and produce 2,3-bis(methoxycarbonyl)-8-methyl-4H-benzopyran () (24%) and 2,3-bis(methoxycarbonyl)-8-methyl-2H-benzopyran () (48%), respectively.

Catalytic synthesis of thiobutyrolactones via CO insertion into the C-S bond of thietanes in the presence of a heterodinuclear organoplatinum-cobalt complex.

Heterodinuclear organoplatinum-cobalt complex having a 1,2-bis(diphenylphosphino)ethane ligand (dppe)MePt-Co(CO)4 catalyzes CO insertion into the C-S bond of thietanes in THF at 100 degrees C under 1.0 MPa of CO for 2 h to give gamma-thiobutyrolactone in quantitative yield.