Search results
Results From The WOW.Com Content Network
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 ...
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 .
Grubbs was instrumental in developing a family of ruthenium catalysts, including Grubbs catalyst for olefin metathesis. [36] He studied olefin transformations for ring-closing metathesis (RCM), [37] cross-metathesis reaction (CMR), [38] and ring-opening metathesis polymerization (ROMP) with cyclic olefins such as norbornene. [39]
Within those non-radical methods, azide-alkyne cycloaddition (also known as click reaction), [18] olefin metathesis [19] among others are utilized to construct sequence-controlled polymers. Depending on these specific chemical reactions, monomers are accurately added to the polymer chain and a well-ordered chain is accomplished stepwise.
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 metal-mediated processes include a carbonyl-olefination and an olefin–olefin metathesis event. There are two general mechanistic schemes to perform this overall transformation: one, reaction of a [M=CHR 1] reagent with an alkene to generate a new metal alkylidene, which then couples with a carbonyl group to form the desired substituted alkene and an inactive [M=O] species (type A); two ...
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 ...