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Catalytic metathesis kinetic studies

Herein, we report the syntheses of new metathesis catalysts Cl2-Ru-(py)2(3-phenylindenylidene) 4a-c. Kinetic studies enabling thorough evaluation of their stabilities and catalytic activities in RCM are also presented. [Pg.31]

Metathesis of alkynes proceeds according to a mechanism (13.177) analogous to that already described for olefins. The formation of catalytically active metal-lacyclobutadiene complexes was confirmed by both kinetic and isotopic studies of... [Pg.713]

The study of reaction [9] affords a unique opportunity to assess the role of the metal in this catalytically important reaction, Scheme 3. As mentioned, the reaction is a degenerate cr-bond metathesis, so that regardless of metal there is the same driving force for the reaction relative to reactants. Thus, the role of the metal can be assessed without the complication of having to separate kinetic and thermodynamic factors. With effective core potentials, the analysis can reasonably include a wide range of main group elements, transition metals, and lanthanides. [Pg.147]

Based on this reactivity, the reaction has been proposed to proceed via the insertion of the carbodiimide into the M-N IxMid of a transient amide complex formed from o-bond metathesis of the precatalyst with the aniline. Turnover occurs via a similar o-bond metathesis of the guanidinate complex with a further equivalent of amine, a reaction that is most likely endothermic based upon pA"a considerations but occurs readily under catalytic conditions [100]. The potential for reversible insertion of the carbodiimide into M-N bonds has been probed by crossover experiments and studies on the current systems do not suggest a reversible insertion step (although this is likely to be a function of the stabihty of the metal-amide generated from carbodiimide extrusion). The molecularity or kinetic competence of... [Pg.208]


See other pages where Catalytic metathesis kinetic studies is mentioned: [Pg.244]    [Pg.196]    [Pg.13]    [Pg.196]    [Pg.68]    [Pg.49]    [Pg.276]    [Pg.22]    [Pg.14]    [Pg.76]    [Pg.327]    [Pg.348]    [Pg.78]    [Pg.339]    [Pg.2]    [Pg.153]    [Pg.40]    [Pg.411]    [Pg.567]    [Pg.79]    [Pg.359]    [Pg.30]    [Pg.459]    [Pg.297]    [Pg.216]    [Pg.76]    [Pg.184]   
See also in sourсe #XX -- [ Pg.157 , Pg.158 ]




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