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首页> 外文期刊>Chemistry: A European journal >Synthesis and Reactivity of Homogeneous and Heterogeneous Ruthenium-Based Metathesis Catalysts Containing Electron-Withdrawing Ligands
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Synthesis and Reactivity of Homogeneous and Heterogeneous Ruthenium-Based Metathesis Catalysts Containing Electron-Withdrawing Ligands

机译：含吸电子配体的均相和多相钌基复分解催化剂的合成及反应性

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The synthesis and heteroge-nization of new Grubbs-Hoveyda type metathesis catalysts by chlorine exchange is described.Substitution of one or two chlorine ligands with tri-fluoroacetate and trifluoromethanesul-fonate was accomplished by reaction of [RuCl_2(=CH-o-iPr-O-C_6H_4)(IMesH_2)](IMesH_2=l,3-bis(2,4,6-trimethyl-phenyl)-4,5-dihydroimidazol-2-ylidene) with the silver salts CF_3COOAg and CF_3SO_3Ag,respectively.The resulting compounds,[Ru(CF_3SO_3)_2(=CH-o-iPr-O-C_6H_4)(IMesH_2)](1),[RuCl(CF_3-SO_3)(=CH-o-iPr-O-C_6H_4)(IMesH_2)](2),and [Ru(CF_3CO_2)_2(=CH-o-iPr-O-C_6H_4)-(IMesH_2)](3)were found to be highly active catalysts for ring-closing metathesis(RCM)at elevated temperature(45 deg C),exceeding known ruthenium-based catalysts in catalytic activity.Turn-over numbers(TONs)up to 1800 were achieved in RCM.Excellent yields were also achieved in enyne metathesis and ring-opening cross metathesis using norborn-5-ene and 7-oxanorborn-5-ene-derivatives.Even more important,3 was found to be highly active in RCM at room temperature(20 deg C),allowing TONs up to 1400.Heterogeneous catalysts were synthesized by immobilizing[RuQ_2(= CH-o-iPr-O-C_6H_4)(IMesH_2)]on a per-fluoroglutaric acid derivatized polystyr-ene-divinylbenzene(PS-DVB)support (silver form).The resulting supported catalyst[RuCl(polymer-CH_2-O-CO-CF_2-CF_2-CF_2-COO)(=CH-o-iPr-O-C_6H_4)(IMesH_2)](5)showed significantly reduced activities in RCM(TONs-380)compared with the heterogeneous analogue of 3.The immobilized catalyst,[Ru(polymer-CH_2-O-CO-CF_2-CF_2-CF_2-COO)(CF_3CO_2)(=CH-o-iPr-O-C_6H_4)(IMesH_2)](4)was obtained by substitution of both Cl ligands of the parent Grubbs-Hoveyda catalyst by addition of CF_3COOAg to 5.Compound 4 can be prepared in high loadings(160 mg catalyst g~(-1)PS-DVB)and possesses excellent activity in RCM with TONs up to 1100 in stirred-batch RCM experiments.Leaching of ruthenium into the reaction mixture was un-precedentedly low,resulting in a ruthenium content <70ppb(ngg~(-1))in the final RCM-derived products.
机译：描述了新型的Grubbs-Hoveyda型复分解催化剂通过氯交换的合成和杂化。[RuCl_2（= CH-o-iPr--）与三氟乙酸酯和三氟甲磺酸酯取代一个或两个氯配体。 O-C_6H_4）（IMesH_2）]（IMesH_2 = 1,3-双（2,4,6-三甲基-苯基）-4,5-二氢咪唑-2-亚烷基）与银盐CF_3COOAg和CF_3SO_3Ag。化合物，[Ru（CF_3SO_3）_2（= CH-o-iPr-O-C_6H_4）（IMesH_2）]（1），[RuCl（CF_3-SO_3）（= CH-o-iPr-O-C_6H_4）（IMesH_2） ]（2），发现[Ru（CF_3CO_2）_2（= CH-o-iPr-O-C_6H_4）-（IMesH_2）]（3）是在高温下用于闭环复分解（RCM）的高活性催化剂（45摄氏度），催化活性超过了已知的钌基催化剂.RCM的周转数（TONs）高达1800.使用炔诺酮复分解和使用norborn-5-的开环交叉复分解也获得了优异的收率。烯和7-氧杂硼烷5烯衍生物。更重要的是，发现3 e在室温（20℃）下在RCM中具有高活性，允许TONs达到1400。通过将[RuQ_2（= CH-o-iPr-O-C_6H_4）（IMesH_2）]固定在全氟戊二酸上合成多相催化剂衍生的聚苯乙烯-二乙烯基苯（PS-DVB）载体（银形式）。所得的负载催化剂[RuCl（聚合物-CH_2-O-CO-CF_2-CF_2-CF_2-COO）（= CH-o-iPr-O- C_6H_4）（IMesH_2）]（5）与3的异相类似物相比，在RCM（TONs-380）中的活性显着降低。固定化催化剂[Ru（polymer-CH_2-O-CO-CF_2-CF_2-CF_2-COO ）（CF_3CO_2）（= CH-o-iPr-O-C_6H_4）（IMesH_2）]（4）是通过将CF_3COOAg加至5来取代母体Grubbs-Hoveyda催化剂的两个Cl配体而获得的在高负荷（160 mg催化剂g〜（-1）PS-DVB）中，在搅拌分批RCM实验中，在TONs高达1100的RCM中具有优异的活性。钌向反应混合物中的浸出空前低，导致钌含量<70ppb（ngg〜（-1））最终的RCM衍生产品。

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