The intermolecular cyclotrimerisation of terminal and internal alkynes can be catalysed by simple cobalt complexes such as a CoBr2(diimine) under mild reaction conditions when treated with zinc and zinc iodide with high regioselectivity in excellent yields.
Can the Ti(OiPr)<sub>4</sub>/<i>n</i>BuLi combination of reagents function as a catalyst for [2+2+2] alkyne cyclotrimerisation reactions?
作者:Gabriela Siemiaszko、Yvan Six
DOI:10.1039/c8nj04931a
日期:——
Catalysis of the cyclotrimerisation of alkynes with the Ti(OiPr)4/nBuLi system was studied, leading to the development of a particularly convenient and reliable protocol. This method allows the [2+2+2] cycloadditionreaction to proceed within a few minutes under microwave conditions, with generally good selectivity from a variety of aromatic and aliphatic alkynes.
研究了用Ti(OiPr)4 / n BuLi体系催化炔烃的环三聚反应,从而开发了一种特别方便和可靠的方案。该方法允许[2 + 2 + 2]环加成反应在微波条件下在几分钟之内进行,对各种芳族和脂族炔烃的选择性通常都很好。
Synthesis and crystal structure of the first metallabicycle cluster 2a-ruthenacyclopent[c,d]indenyl-triruthenium undecacarbonyl Ru4(CO)11C15H14
作者:Petra Escarpa Gaede、Simon Parsons、Brian F.G. Johnson
DOI:10.1016/s0022-328x(96)06427-3
日期:1996.11
The metallabicycle clusterRu4(CO)11C15H14,1 has been obtained from the reaction between Ru3(CO)12 with 1,3,5-triisopropenylbenzene and represents the firstclustercontaining a metallabicycle unit. The organo-ligand is bonded through 3π and 4σ bonds to the Ru3 metal triangle, donating a total of ten electrons. In all, four CH bonds have been cleaved in the original ligand.
4-trisisopropenylbenzene ( II ) was investigated by gas-phaseUVphotoelectron spectroscopy (UPS) and theoretical (HAM 3) calculations. In the case of compound I we found that the geometrical parameters do not effect appreciably the ordering and spacing of the highest occupied molecular orbitals whereas in II agreement between experimental and calculated IEs was found only for some geometries, characterized also by
摘要 通过气相紫外光电子能谱(UPS)和理论(HAM 3)计算研究了1,3,5-三异丙烯基苯(I)和1,2,4-三异丙烯基苯(II)的结构。在化合物 I 的情况下,我们发现几何参数不会显着影响最高占据分子轨道的排序和间距,而在 II 中,实验和计算 IE 之间的一致性仅在某些几何结构中发现,其特征还在于总能量最低。这种差异反映在两个分子的能级间距上。
Hydrogen-Bonding Controlled Nickel-Catalyzed Regioselective Cyclotrimerization of Terminal Alkynes
作者:Kai Yang、Pengfei Wang、Ze-Ying Sun、Minjie Guo、Wentao Zhao、Xiangyang Tang、Guangwei Wang