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 2-butenes are then subjected to metathesis with ethylene. Rhenium- and molybdenum-containing heterogeneous catalysis are used. Nowadays, only the "reverse" reaction is practiced, i.e., the conversion of ethylene and 2-butene to propylene: [2] CH 2 =CH 2 + CH 3 CH=CHCH 3 → 2 CH 2 =CHCH 3
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 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 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:
Corey-Seebach reaction; Corey–Winter olefin synthesis; Corey–Winter reaction; Cornforth rearrangement; Coupling reaction; Crabbé reaction; Craig method; Cram's rule of asymmetric induction; Creighton process; Criegee reaction; Criegee rearrangement; Cross metathesis; Crum Brown–Gibson rule; Curtius degradation; Curtius rearrangement ...
This carbene collapses with loss of carbon dioxide to give the olefin. Proposed Mechanism of the Corey-Winter Olefination. An alternative mechanism does not involve a free carbene intermediate, but rather involves attack of the carbanion by a second molecule of trimethylphosphite with concomitant cleavage of the sulfur-carbon bond.
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. [6]