Activation of Small Polar Molecules by Environmentally Benign Transition Metal Catalysts

由于我们已经发现，在第8-10族过渡金属配合物中，低价钌配合物特别显示出对杂原子如N、S和O原子的高亲和力，因此研究了钌催化剂对小极性分子的特征活化。结果，我们成功地开发了以下新颖的铼催化的碳-碳和碳-杂原子键形成反应; 1）亚磺酰胺与缺电子炔的高度区域选择性和立体选择性加成，导致多官能烯烃，2）通过炔的异构化和连续的Diels-Alder反应，将炔与缺电子烯烃正式[4+2]环加成为环己烯二羧酸酯，3）通过环丁烯酮的碳-碳键断裂重构合成2-吡喃酮、环戊烯和环己烯酮; 4）三种不同炔的[2+2+2]共环化（乙炔二羧酸二甲酯、1-癸炔和3-己炔），5）不同烯烃的区域和立体选择性共聚合此外，我们还成功地通过Ru（0）的选择性配体置换，合成了多种Ru（0）配合物（η^6- 1，3，5-环辛三烯）（η^2-富马酸二甲酯）_2（1）是本实验室于1999年首次合成的。进一步的研究表明，1与苯酚的化学计量反应得到了新的Ru（II）苯酚配合物，而1与水在1，2-二（二苯基膦基）乙烷（dppe）存在下的反应得到了新的手性Ru（0）水配合物Ru（η ^2-dppe）（η^2-富马酸二甲酯）_2（H_2O）（2）。采用高效液相色谱手性柱成功地对rac-2进行了光学拆分。通过核磁共振数据和密度泛函理论研究，揭示了配位水的旋转和反转行为。

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.