Talk:Cumene process
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[edit]I like the mention of Chemical engineering, but 'chemical engineering at its best'? --Morbid-o 20:23, 25 Mar 2005 (UTC)
wrong mechanism?
[edit]There should be a -H+ on the last reaction arrow... lg phil--90.136.95.123 (talk) 17:18, 17 May 2010 (UTC)
The mechanism is unreferenced, and something seems wrong with the hydrolysis part show below: The hydroperoxide is protonated, then water leaves--leaving behind a cationic intermediate featuring a terminal, positively charged oxygen--which then rearranges into the resonance stabilized carbocation. It's the middle structure in the scheme that seems wrong, and it's not obvious how it rearrange into the next structure.
[[Image:Cumene-process-phenyl-migration-2D-skeletal.png|400px|center]][File no longer corresponds to incorrect rxn scheme Yilloslime (t) 06:05, 15 August 2008 (UTC)]
A much more plausible mechanism, to me at least, would be protonation of the hydroperoxy group followed by a concerted phenyl shift from the benzyl carbon to the oxygen which would kick out water while directly forming the oxygen stabilized carbocation pictured on the right without going the very high energy intermediate featured in the middle of the above figure.
An alternative 2 step mechanism would involve participation by a neighboring phenyl π-bond to kick out H2O and generate an epoxy intermediate with a resonance stabilized carbocation which could rearrange into the carbocation show above right. If have chemdraw I'd draw what i'm talking about. Anyone know what's correct here? Yilloslime (t) 01:28, 14 August 2008 (UTC)
- Checking with the ole textbook collection shows that it is indeed the concerted mechanism. I have corrected the text of the article and deleted the incorrect figure, but due to lack of ChemDraw, I cannot produce a corrected figure. Yilloslime (t) 03:13, 14 August 2008 (UTC)
I made the image, but I only based it on the text of this revision of the article. I'll make a new image now.
Ben (talk) 10:16, 14 August 2008 (UTC)
- Is this the sort of thing you are proposing? If yes, I'll upload it to Commons. If not, let me know what alterations to make.
- Bingo! That's it. Thanks. (I couldn't find a drawing of this step in any of my textbooks, but this scheme makes a lot more sense, and is consistent with Streitwieser & Heathcock's description of it being analogous to Baeyer-Villigar oxidation and Vollhardt's analogy to the oxidation step in hydroboration-oxidation.) Yilloslime (t) 15:21, 14 August 2008 (UTC)
OK, the new image is available under the same name as the old one (sorry if that causes problems illustrating this discussion!).
Ben (talk) 19:16, 14 August 2008 (UTC)
IUPAC names
[edit]Shouldn't the article stick to some consistency in naming chemical compounds? You have benzene and phenol in the first paragraph, but then there's also acetone and propylene, known as propanone and propene respectively in IUPAC nomenclature. Is it possible to just stick with one convention for naming compounds? Nonagonal Spider (talk) 06:00, 11 November 2008 (UTC)
Is m-crseol mass produced by the cumene process too?
[edit]this version of m-cresol describes that n-propane alkylates toluene to yield isomers of cymene. Cymene is then oxidatively dealkylated analogous to the cumene process. --- Ktsquare (talk) 00:00, 16 October 2018 (UTC)
If expanded, the inclusion of how to make m-cresol shall be slotted inside Cumene_process#Alternatives_to_phenol_production. --- Ktsquare (talk) 21:53, 27 December 2020 (UTC)