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In organic chemistry, olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds. [ 1 ] [ 2 ] Because of the relative simplicity of olefin metathesis, it often creates fewer undesired by-products and hazardous wastes than alternative ...
Grubbs's main research interests were in organometallic chemistry and synthetic chemistry, particularly the development of novel catalysts for olefin metathesis. In olefin metathesis, a catalyst is used to break the bonds of carbon molecules, which can then re-form to create chemical bonds in new ways, producing new compounds with unique ...
Often, however, cross-coupling refers to a metal-catalyzed reaction of a nucleophilic partner with an electrophilic partner. Mechanism proposed for Kumada coupling (L = Ligand , Ar = Aryl ). In such cases, the mechanism generally involves reductive elimination of R-R' from L n MR(R') (L = spectator ligand ).
Olefin metathesis is a formal exchange of the alkylidene fragments in two alkenes. It is a catalytic reaction with carbene , or more accurately, transition metal carbene complex intermediates. In this example ( ethenolysis , a pair of vinyl compounds form a new symmetrical alkene with expulsion of ethylene .
Grubbs catalysts are of interest for olefin metathesis. [ 25 ] [ 26 ] It is mainly applied to fine chemical synthesis. Large-scale commercial applications of olefin metathesis almost always employ heterogeneous catalysts or ill-defined systems based on ruthenium trichloride.
The reaction is an example of cross metathesis. The utility of the reaction is driven by the low cost of ethylene as a reagent and its selectivity. It produces compounds with terminal alkene functional groups (α-olefins), which are more amenable to other reactions such as polymerization and hydroformylation. The general reaction equation is:
The Shell higher olefin process (SHOP) is a chemical process for the production of linear alpha olefins via ethylene oligomerization and olefin metathesis invented and exploited by Shell plc. [1] The olefin products are converted to fatty aldehydes and then to fatty alcohols , which are precursors to plasticizers and detergents .
The mechanism of homogeneous ring-opening metathesis polymerization is well-studied. It is similar to any olefin metathesis reaction. Initiation occurs by forming an open coordination site on the catalyst. Propagation happens via a metallacycle intermediate formed after a 2+2 cycloaddition. When using a G3 catalyst, 2+2 cycloaddition is the ...