Facile Synthesis of Effcient and Selective Ruthenium Olefin Metathesis Catalysts with Sulfonate and Phosphate Ligands
作者:Peili Teo、Robert H. Grubbs
DOI:10.1021/om1007924
日期:2010.11.22
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.
Building Stereoselectivity into a Chemoselective Ring-Opening Metathesis Polymerization Catalyst for Alternating Copolymerization
作者:Sebastian Torker、Andre Müller、Peter Chen
DOI:10.1002/anie.200906846
日期:——
This way and that: Ruthenium complexes with asymmetric bidentate phosphine ligands bearing two substituents that differ in size (green spheres) produce a totally alternating copolymer of norbornene and cyclooctene by ring‐opening metathesis polymerization (ROMP). The E/Z ratio can be influenced systematically by changing the bulkiness of the aryl sulfonate ligand (blue rectangles).
这样的方式:具有不对称双齿膦配体的钌配合物带有两个大小不同的取代基(绿色球体),通过开环复分解聚合(ROMP)生成降冰片烯和环辛烯的完全交替的共聚物。的E / Z 比率可以系统通过改变芳基磺酸盐配位体(蓝色矩形)的体积的影响。
Chiral NHC Ligands for Enantioselective Gold(I) Catalysis Under Aerobic Conditions: the Importance of Conformational Flexibility and Steric Hindrance of NHC Ligand on Reactivity
of chiral NHC−Au−Cl complexes, bearing sterically encumbered NHC ligands, has been accessed by merging anilines with commercially available chiral aminoalcohols and amines. Evaluation of the catalytic activity in enantioselective allenol cyclization has pointed out the importance of the steric hindrance and conformationalflexibility of the NHC core for reactivity. Ion metathesis between NHC−Au−Cl