Talk:Olefin metathesis

General conditions

What are the general conditions for this reaction? Which specific catalysts are used? -- Rune Welsh ταλκ 15:17, 5 October 2005 (UTC)

Nobel prize

Request can someone who uderstands this add a plain english paragraph of why this disocery is important engough for a nobel prize?--Duk 17:18, 5 October 2005 (UTC)

Maybe because they made an important contribution to the field of chemistry. Whether or not you understand it makes no difference. I hereby award you the Nobel Prize for Assholery. (Unsigned comment by User:Duesling)

I guess I don't understand how asking for something to be explained, by someone who understands it, is being an asshole. Wikilove and happy editing! :) --Duk 00:46, 6 October 2005 (UTC)

Use

Some information on what this is useful for would be nice. --Guthrie 11:53, 6 October 2005 (UTC)

Reorganized article

I reorganized the article so the more basic, layman's information is first, followed by most of the technical jargon that would just drive off the average reader before they understand the significance of the reaction and why this particular bit of chemistry, among thousands of other discoveries, won a nobel prize.

Duesling, calm down, eh? This is an encyclopedia, not a chemistry journal. :)

  — J’raxis (T) 01:57, 7 October 2005 (UTC)

Types of metathesis

"for the development of the metathesis method in organic synthesis"" was the reason for Nobel prize. Is olefin metathesis one type of metathesis or are these two things equal? -EnSamulili 09:52, 8 October 2005 (UTC)

It's a type of metathesis. See alkyne metathesis. -- Rune Welsh ταλκ 10:10, 8 October 2005 (UTC)

Example

This is a stereoselective bu NOT an enantionselective reaction. Perhaps it is with a chiral catalystst but without chiral information it isn't!

The title of the article in the footnote citation for that reaction is listed as "A Recyclable Chiral Ru Catalyst for Enantioselective Olefin Metathesis. Efficient Catalytic Asymmetric Ring-Opening/Cross Metathesis in Air", so one might presume that the catalyst for the reaction is indeed chiral. DMacks 18:10, 10 July 2006 (UTC)

4 groups vs 2

In the formula in the leading paragraph, each reactants has 4 groups attached, and two from one reactant are exchanged for two from the other. In the explaining formula in the overview paragraph, each reactant has only two groups attached, and one is exchanged for one. This should be explained/harmonized. AxelBoldt 02:46, 3 September 2006 (UTC)

SHOP

Olefin metathesis was first used in petroleum reformation for the synthesis of higher olefins in the Shell higher olefin process (SHOP) under high pressure and high temperatures.

The sentence is ambigous. It can mean

(1) olefin metathesis was first used in SHOP, for petroleum reformation, or

(2) the first use of olefin methathesis in petroleum reformulation was SHOP.

Also, does SHOP use a metal catalyst? AxelBoldt 03:04, 3 September 2006 (UTC)

Where is the article?

I can't seem to link from the Richard Schrock article to this one, but i get the message saying that I can put up a request for it, start it, look for it etc. Is the problem on my end or on the encyclopedi's end?

A good link exists already at the top of para 3 of Richard Schrock to olefin metathesis.--Smokefoot 23:43, 18 September 2006 (UTC)

Metathesis; a word

Metathesis is basically just a word to describe the transfere of bonds between two chemically similar molecules, ie RCM "swapping" what is attached to the double bonds. Olefin metathesis is an archaic(? my spelling is crap) name for alkene metathesis--> this name ought to be changed. This page should also be a sub page of a main metathesis page. Alkene metathesis can be either ring opening, closing or polymeric, depending on what you do with it. Any references to Schrock in this article should be brief as he should be covered by alkyne metathesis. On an importance scale alkene metathesis is much better for organic synthesis. The reason Schrock and Grubbs won their nobel prizes was because they developed new, stereoselective ways of forming carbon-carbon bonds, this is (suprisingly) one of the hardest things to do. The chemistry they have pioneered is very elegant as it occurs at low temp and may be used in complex matrices such as peptides/proteins, no mean feat. So, this is quite a good page but is looking about 20 years behind in content. If you cared to look up Robinson/Eldaridi and/or Ghalit/Poot you would find prime examples of how metathesis is important. User:[Spgoo1] [User talk:Spgoo1|talk] • contribs) 10:56, 4 March 2007 (UTC).

• • I disagree, and personally prefer olefin metathesis, a quick google shows olefin metathesis gets 159 000 hits, whilst alkene metathesis gets 22 000 Seansheep 23:14, 8 October 2007 (UTC)

First figure

The first figure in this article is absolutely terrible. The cyclobutane is depicted as being a transition state which is total nonsense and completely misleading. The [2+2] cycloaddition of two olefins is symmetry forbidden and thus an extremely high energy process. If that was the mechanism, then olefin metathesis would never happen! The second scheme is much better because it shows the correct cyclometallobutane intermediate. The first figure should be edited to remove the "transition state" Wjousts 14:09, 10 October 2007 (UTC)

The first figure is explicitly marked "general scope is outlined by the following equation". The square-bracketed piece illustrates the overall changes that occur but is not intended to convey any mechanistic detail (it has no electron-flow and doesn't have a double-dagger T-state symbol). I thinp placing the two starting materials aligned and thinking about "the bonding pattern simply swaping around" is a great way to see what happens overall. And a terrible mechanistic suggestion, but that's not the point of this diagram. I'd love to have a better "no implied mechanism" diagram that illustrates the overall transformation taking place here. DMacks 16:23, 10 October 2007 (UTC)

• agree with DMacks , it is not implied anywhere in the article that the first image depicts a reaction mechanism, so in practical terms the image stays or somebody comes up with a better one. V8rik 20:51, 10 October 2007 (UTC)

The image clearly implies something about mechanism which is totally wrong! The article is better off without it. Wjousts 22:09, 10 October 2007 (UTC)

Okay, I've changed it for another one which shows the alignment without being wrongly suggestive of mechanism. Wjousts 22:22, 10 October 2007 (UTC)

Looks fine to me. DMacks 01:44, 11 October 2007 (UTC)

• new image looks great, thanks for the effort V8rik 15:24, 11 October 2007 (UTC)

Second Image

I think the second image has the wrong reactant in the top left slide. It should be R1-=-R2 not R2-=-R2. I'll change the svg if someone more knowledgeable confirms this. This doesn't match the first image. --RabidRabbit23 (talk) 19:57, 23 September 2009 (UTC)

• thanks for spotting the error, I have made the change. V8rik (talk) 20:18, 23 September 2009 (UTC)

Catalysts

This section of the page does not require all of those pictures. A simple link to each of the respective catalysts pages, with just the first gen grubbs catalyst in a nice captioned box to the side would suffice greatly. Also, the talk about the Hoveyda-Grubbs catalyst is excessive. This is clearly covered in the page about grubbs catalysts. — Preceding unsigned comment added by 82.26.226.187 (talk) 16:35, 20 February 2013 (UTC)

Mechanism

The overall mechanism is fine, but the discussion about thermodynamics needs work. "energetics" is not a meaningful term. The issue is enthalpy and entropy. The reactants and products have nearly the same enthalpy. Thus, the reaction must be driven by entropy -- that is, by Le Chatelier's principle. There are probably specific rationales for different reactions, but certainly for RCM it is the low concentration of ethene (which evaporates from the reaction mixture) that drives the reaction forward.

It would be good to point out that all scrambling possibilities are possible and active, but some of them produce products that are the same as the reactants and so are not observed. Hansonrstolaf (talk) 11:56, 18 April 2018 (UTC)

Useful comments. Some of these reactions involve strained alkenes of the norbornene variety, and these reactions probably have an enthalpic component, which is probably known.--Smokefoot (talk) 14:22, 18 April 2018 (UTC)

types of olefin metathesis -- adding more?

For the Types_of_olefin_metathesis_processes section, a journal article discusses propene, butene, isobutene and 2-methylbut-2-ene. Shall the section expand to include those heavier alkenes than ethene?

The article should not imply that only ethylene is used, but if it does please correct it. The unusual feature of the article is the emphasis on large scale metatheses, which are exclusively catalyzed heterogeneously and that these catalysts were developed before the Nobelists even started their work.--Smokefoot (talk) 23:07, 2 September 2020 (UTC)

References

Sorta unfortunate

So far as I can tell, heterogeneously catalyzed olefin metathesis, commercialized before Schrock and Grubbs published their first papers, appears to be the dominant app, at least in a tonnage sense. This article seems unbalanced since in terms of word count, it heavily focuses on the academic homogenous research, especially mechanistic work.--Smokefoot (talk) 19:01, 28 November 2024 (UTC)