A medium fluorous Grubbs–Hoveyda 2nd generation catalyst for phase transfer catalysis of ring closing metathesis reactions
摘要:
A fluorous Grubbs-Hoveyda metathesis catalyst supported on Teflon (R) powder, that readily moves between the solid phase (Teflon (R)) and the liquid phase (DMF) was prepared. By modulating the hydrophobicity of the reaction medium at the end of the reaction, the supported catalyst could be recovered by simple filtration even though the catalyst existed in a homogeneous state during the reaction. In RCM reactions, the catalyst could be reused up to three times with only a slight loss in reactivity with each subsequent cycle. (C) 2015 Elsevier Ltd. All rights reserved.
A Unique Ruthenium Carbyne Complex: A Highly Thermo-endurable Catalyst for Olefin Metathesis
作者:Mingbo Shao、Lu Zheng、Weixia Qiao、Jingjing Wang、Jianhui Wang
DOI:10.1002/adsc.201200119
日期:2012.10.8
A cationic rutheniumcarbynecomplex was prepared and was found to initiate olefinmetathesis reactions with good activities, which throws a new light on the design of a new type of rutheniumcatalyst for RCM reactions. More importantly, no double bond isomerized by-product was observed even at elevated temperatures in reactions catalyzed by the new carbynecomplex. A mechanism involving the in situ
PQS-2: ring-closing- and cross-metathesis reactions on lipophilic substrates; in water only at room temperature, with in-flask catalyst recycling
作者:Bruce H. Lipshutz、Subir Ghorai
DOI:10.1016/j.tet.2009.11.010
日期:2010.1
(PQS-2) of the recently introduced PQS is described. It forms catalytic nanomicellar reactors in water that provide the medium for highly reactive Ru carbene catalysts to effect both ring closing metathesis to trisubstituted olefins and cross-metathesis reactions at roomtemperature. The catalyst can be recycled without removal from the reaction vessel.
Synthesis and reactivity of oxygen chelated ruthenium carbene metathesis catalysts
作者:Yiran Zhang、Mingbo Shao、Huizhu Zhang、Yuqing Li、Dongyu Liu、Yu Cheng、Guiyan Liu、Jianhui Wang
DOI:10.1016/j.jorganchem.2014.01.017
日期:2014.4
and the terminal oxygen of the benzylidene ether are both coordinated to the metal to give an octahedral structure. However, the carbonyl oxygen of complexes (H2IMes)(Cl)2RuC(H)[(C6H3X)OCH(CH2C(O)OCH2)(X = H, OMe)] does not coordinate to the metal due to the steric effect of the lactone. All these complexes were used as catalysts for olefin metathesis reactions and all exhibited excellent performances
Ferrocene Redox Controlled Reversible Immobilization of Ruthenium Carbene in Ionic Liquid: A Versatile Catalyst for Ring-Closing Metathesis
作者:Guiyan Liu、Haiyan He、Jianhui Wang
DOI:10.1002/adsc.200800713
日期:2009.7
A ferrocene‐tagged rutheniumcarbene 15 that can be reversibly immobilized in an ionicliquid (IL) via the controlled oxidation and reduction of a ferrocene tag was prepared. This offers a new strategy which uses redox chemistry to controlimmobilization and to recycle both the catalyst and the IL. In this experiment, 11 recycles were performed for the ring‐closing metathesis (RCM) of a substrate using
Recycling a Homogeneous Catalyst through a Light-Controlled Phase Tag
作者:Guiyan Liu、Jianhui Wang
DOI:10.1002/anie.200906034
日期:2010.6.14
A homogeneous ruthenium–carbene complex was tagged with a light‐responding nitrobenzospiropyran group to control its solubility through reversible conversion between its neutral (lipophilic) and ionic (lipophobic) states using light irradiation (see scheme; Mes=mesityl). This tagged complex has significant catalytic activity in ring‐closing metathesis reactions and was recycled several times.
均匀的钌-卡宾络合物带有一个光响应性硝基苯并螺吡喃基团,以通过使用光辐照在其中性(亲脂性)和离子性(疏脂性)状态之间可逆转换来控制其溶解度(参见方案; Mes = mesityl)。这种标记的复合物在闭环复分解反应中具有显着的催化活性,并被回收了数次。