| Co-Investigator(Kenkyū-buntansha) |
MITSUDO Take-aki Kyoto Univ., Graduate School of Eng., Professor, 工学研究科, 教授 (90026344)
WADA Kenji Kyoto Univ., Graduate School of Eng., Lecturer, 工学研究科, 講師 (10243049)
URA Yasuyuki Kyoto Univ., Graduate School of Eng., Instructor, 工学研究科, 助手 (40335196)
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| Research Abstract |
Since we have already found that among group 8-10 transition metal complexes, low-valent ruthenium complexes especially show high affinity to heteroatoms such as N, S, and O atoms, characteristic activation of small polar molecules by ruthenium catalysts was investigated. As a result, we have succeeded in developing the following novel ruthenium-catalyzed carbon-carbon and carbon-heteroatom bond forming reactions ; 1)highly regio- and stereoselective addition of sulfenamides to electron-deficient alkynes leading to polyfunctional alkenes, 2)formal [4+2] cycloaddition of alkynes with electron-deficient alkenes to cyclohexenedicarboxylates via isomerization of alkynes and successive Diels-Alder reaction, 3)reconstructive synthesis of 2-pyranones, cyclopentenes, and cyclohexenones via carbon-carbon bond cleavage of cyclobutenones, 4)[2+2+2] cocyclization of three different alkynes (dimethyl acetylenedicarboxylate, 1-decyne and 3-hexyne), 5)regio- and stereoselective codimerization of different alkenes (2-norbornenes with acrylic compounds, and dihydrofurans with α,β-unsaturated esters).
In addition, we succeeded in preparation of various Ru(0) complexes via selective ligand displacement of Ru(η^6-1,3,5-cyclooctatriene)(η^2-dimethyl fumarate)_2 (1), which was originally synthesized in our laboratory in 1999. Further study revealed that the stoichiometric reaction of 1 with phenol gave novel Ru(II) phenolate complexes, while the reaction of 1 with water in the presence of 1,2-bis(diphenylphosphino)ethane (dppe) gave a novel chiral Ru(0) aqua complex, Ru(η^2-dppe)(η^2-dimethyl fumarate)_2(H_2O) (2). Optical resolution of rac-2 was successfully performed by HPLC equipped with a chiral column. On the basis of the VT NMR data and DFT study, the behavior of the coordinated water (rotation and inversion) was disclosed.
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