诸如硅之类的主族元素化合物是绿色且廉价催化剂的诱人候选物。为了使它们与最先进的过渡金属配合物竞争,必须解锁和控制新的反应模式,这可以通过应变来实现。使用三(2-炔基)甲基phosph([TSMPH 3 ] +)支架,我们制备了应变阳离子硅烷[TSMPSiH] +。与一般的氢键Si-H键形成鲜明对比的是,它在4.7–8.1的实验性p K a DMSO中呈酸性,低于苯酚,苯甲酸和少数报道的p K a的氢化硅烷。价值观。我们表明,环应变显着地促进了这种异常的酸度以及感应和静电作用。共轭碱TSMPSi在CH酸存在下活化THF分子,从而通过痕量的[TSMPSiH] +起到释放应变路易斯酸的作用,从而产生高通量的烷氧基硅烷。该反应涉及从Si II到Si IV的正式氧化态变化,与过渡金属介导的过程具有令人着迷的相似性。
诸如硅之类的主族元素化合物是绿色且廉价催化剂的诱人候选物。为了使它们与最先进的过渡金属配合物竞争,必须解锁和控制新的反应模式,这可以通过应变来实现。使用三(2-炔基)甲基phosph([TSMPH 3 ] +)支架,我们制备了应变阳离子硅烷[TSMPSiH] +。与一般的氢键Si-H键形成鲜明对比的是,它在4.7–8.1的实验性p K a DMSO中呈酸性,低于苯酚,苯甲酸和少数报道的p K a的氢化硅烷。价值观。我们表明,环应变显着地促进了这种异常的酸度以及感应和静电作用。共轭碱TSMPSi在CH酸存在下活化THF分子,从而通过痕量的[TSMPSiH] +起到释放应变路易斯酸的作用,从而产生高通量的烷氧基硅烷。该反应涉及从Si II到Si IV的正式氧化态变化,与过渡金属介导的过程具有令人着迷的相似性。
Alkylidenverbrückte, symmetrische, zweikernige Metallocenkomplexe als Katalysatoren für die Propylenpolymerisation
作者:Matthias Deppner、Ralf Burger、Marc Weiser、Helmut G. Alt
DOI:10.1016/j.jorganchem.2004.10.056
日期:2005.6
synthesis is described of symmetric alkylidene bridged dinuclear zirconocenecomplexes. The influence of structural parameters and different cocatalysts such as methylaluminoxane (MAO), triphenyl tetrakis(pentafluorophenyl)borate- or tris(pentafluorophenyl)borane has been investigated for homogeneous propylene polymerization. The dinuclear catalysts show highest polymerization activities by activation
Intramolecular ionic interactions in bolaform electrolytes of .alpha.,.omega.-bis(9-fluorenyl)polymethylenes
作者:G. L. Collins、J. Smid
DOI:10.1021/ja00786a026
日期:1973.3
Formation of tetrabenzodispiro[4.0.4.3]tridecatetraene by a titanium mediated fluorenyl coupling reaction
作者:Cornelia Fritze、Gerhard Erker、Roland Fröhlich
DOI:10.1016/0022-328x(95)05588-g
日期:1995.10
Treatment of 1,3-propanediol-ditosylate with fluorenyllithium yields 1,3-bis(fluorenyl)propane (5). Subsequent addition of methyllithium gives the corresponding dilithio compound 6. Dilithio-1,3-bis(fluorenyl)propane (6) was treated with titanium tetrachloride to yield the organic tetrabenzodispiro[4.0.4.3]tridecatetraene product 7, presumably formed by means of a carbon-carbon coupling reaction involving substituted fluorenyl radicals. The organic compounds 5 and 7 were identified by X-ray crystal structure analyses.