Synthesis and Reactivity of Olefin Metathesis Catalysts Bearing Cyclic (Alkyl)(Amino)Carbenes
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چکیده
منابع مشابه
Synthesis and reactivity of olefin metathesis catalysts bearing cyclic (alkyl)(amino)carbenes.
The evolution of olefin metathesis into a reaction routinely used to form new carbon–carbon double bonds has been enabled by the development of well-defined transition-metal catalysts. [1,2] Many metathesis catalysts based on the [L2X2Ru=CHR] scaffold have been synthesized in an effort to increase catalyst stability, activity, and substrate scope.[3–10] A significant gain in these areas was ach...
متن کاملKinetic Selectivity of Olefin Metathesis Catalysts Bearing Cyclic (Alkyl)(Amino)Carbenes.
The evaluation of ruthenium olefin metathesis catalysts 4-6 bearing cyclic (alkyl)(amino)carbenes (CAACs) in the cross-metathesis of cis-1,4-diacetoxy-2-butene (7) with allylbenzene (8) and the ethenolysis of methyl oleate (11) is reported. Relative to most NHC-substituted complexes, CAAC-substituted catalysts exhibit lower E/Z ratios (3:1 at 70% conversion) in the cross-metathesis of 7 and 8. ...
متن کاملRuthenium Olefin Metathesis Catalysts Bearing Carbohydrate-Based N-Heterocyclic Carbenes.
Ru-based olefin metathesis catalysts containing carbohydrate-derived NHCs from glucose and galactose were synthesized and characterized by NMR spectroscopy. 2D-NMR spectroscopy revealed the presence of Ru-C (benzylidene) rotamers at RT and the rate of rotation was measured using magnetization transfer and VT-NMR spectroscopy. The catalysts were found to be effective at ring-opening metathesis p...
متن کاملSynthesis of Molybdenum Olefin Metathesis Catalysts through Protonation Reactions
Chapter 1 The attempted syntheses of molybdenum imido alkylidene complexes of the type Mo(NArc,)(CH-t-Bu)[Biphen] and Mo(N-2-CF 3C6H4)(CHCMe 2Ph)[Biphen] (Biphen2 = 3,3'-di-t-butyl-5,5',6,6'-tetramethyl1,1'-biphenyl-2,2'-diolate) from Mo(NArcl)(CH-tBu)(OTf)2(dme) and [Biphen]K2 have sporadically afforded mixtures containing the desired products along with the corresponding amido alkylidyne comp...
متن کاملWell-defined silica-supported olefin metathesis catalysts.
Two triethoxysilyl-functionalized N-heterocyclic carbene ligands have been synthesized and used to prepare the corresponding second-generation ruthenium olefin metathesis catalysts. These complexes were then grafted onto silica gel, and the resulting materials were efficient heterogeneous catalysts for a number of metathesis reactions. The solid-supported catalysts were shown to be recyclable o...
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ژورنال
عنوان ژورنال: Angewandte Chemie International Edition
سال: 2007
ISSN: 1433-7851,1521-3773
DOI: 10.1002/anie.200702085