Facile Synthesis of Effcient and Selective Ruthenium Olefin Metathesis Catalysts with Sulfonate and Phosphate Ligands
摘要:
A series of novel, air-stable ruthenium NHC catalysts with sulfonate and phosphate anions have been prepared easily in one pot at high yields using commercially available precursors. The catalysts were found to be effective for ring-opening metathesis polymerization, ring-closing metathesis, and cross-metathesis. The catalysts showed higher cis-selectivity in olefin cross-metathesis reactions as compared to earlier known ruthenium-based olefin metathesis catalysts, with allylbenzene and cis-1,4-diacetoxybutene as substrates.
Studies on the Himbert Intramolecular Arene/Allene Diels–Alder Cycloaddition. Mechanistic Studies and Expansion of Scope to All-Carbon Tethers
作者:Yvonne Schmidt、Jonathan K. Lam、Hung V. Pham、K. N. Houk、Christopher D. Vanderwal
DOI:10.1021/ja4025963
日期:2013.5.15
The unusual intramolecular arene/allene cycloaddition described 30 years ago by Himbert permits rapid access to strained polycyclic compounds that offer great potential for the synthesis of complex scaffolds. To more fully understand the mechanism of this cycloaddition reaction, and to guide efforts to extend its scope to new substrates, quantum mechanical computational methods were employed in concert
Decomposition Pathways of <i>Z</i>-Selective Ruthenium Metathesis Catalysts
作者:Myles B. Herbert、Yu Lan、Benjamin K. Keitz、Peng Liu、Koji Endo、Michael W. Day、K. N. Houk、Robert H. Grubbs
DOI:10.1021/ja301108m
日期:2012.5.9
The decomposition of a Z-selective rutheniummetathesiscatalyst and structurally similar analogues has been investigated utilizing X-ray crystallography and density functional theory. Isolated X-ray crystal structures suggest that recently reported C-H activated catalysts undergo decomposition via insertion of the alkylidene moiety into the chelating ruthenium-carbon bond followed by hydride elimination
已经利用 X 射线晶体学和密度泛函理论研究了 Z 选择性钌复分解催化剂和结构相似类似物的分解。孤立的 X 射线晶体结构表明,最近报道的 CH 活化催化剂通过将亚烷基部分插入螯合的钌 - 碳键然后氢化物消除而发生分解,这得到了理论计算的支持。所得的氢化钌中间体与先前观察到的烯烃迁移有关,因此导致交叉复分解反应中产生不需要的副产物。防止这些分解模式对于设计更具活性和选择性的 Z 选择性催化剂至关重要。