Talk:Gattermann reaction

Zinc cyanide variant

The Gattermann reaction is the formylation of an aromatic ring with Zn(CN)2 + HCl (or HCN + HCl + Lewis acid), which forms an imine intermediate which is hydrolyzed to an aldehyde. ChristianB 22:20, 26 July 2007 (UTC)

• for some reason we call that reaction the Gattermann aldehyde synthesis V8rik 17:15, 27 July 2007 (UTC)

Which now is a redirect back to this page (all the Gattermann-like reactions together). Thanks User:Project Osprey! DMacks (talk) 13:06, 24 September 2014 (UTC)

Poli-ambiguation? Gattermann reaction is not Gattermann aldehyde synthesis. Wiki in trouble?

First note this: Articles on Gattermann reaction and Gattermann aldehyde synthesis discuss same reaction but Gatterman-Aldehyde reaction redirects to a subsection in Formylation reaction (on 19:44, 22 September 2011 (UTC)) . This is one problem (or fault).

The other is wikipedia doesn't have a reaction in the name of Gattermann reaction (nor anything similar) where Diazonium chloride is converted into haloarene in presence of copper powder and Halogen acid.

But wikipedia do have a discussion on the 'common' Gattermann reaction at Nucleophilic_aromatic_substitution#Nucleophilic_aromatic_substitution_reactions but the link just go to Gattermann aldehyde synthesis on the 'name' Gattermann reaction

Gattermann reactions are of several types and the one which we commonly refer to by simply saying Gattermann reaction is the preparation of haloarenes (–Cl or –Br) from Diazonium salt by treating the latter with hydrogen halide in presence of copper powder

Here is an abstract from http://onlinelibrary.wiley.com/doi/10.1002/9780470638859.conrr265/abstract

The preparation of aromatic halides or aromatic cyanides by decomposition of corresponding diazo salts in the presence of copper powder, in which copper powder is freshly obtained from a copper (II) sulfate aqueous solution, is generally referred to as the Gattermann reaction. It is believed that a radical mechanism might be involved in this reaction, by which electron transfer occurs at the surface of metallic copper. This reaction is useful for the preparation of aromatic halides and cyanides.

For disambiguation here is another abstract from http://onlinelibrary.wiley.com/doi/10.1002/0471264180.or009.02/abstract,

Gatterman developed two methods for introducing the aldehdye group into aromatic compounds. The first of these known as the Gatterman Koch reaction uses a mixture of carbon monoxide and hydrogen chloride in the presence of a mixture of anhydrous aluminum chloride and cuprous chloride. It is not adaptable to the preparation of aldehydes from phenols or phenolic ethers, however. The second method employs a mixture of hydrogen cyanide and hydrogen chloride with or without a catalyst and permits the introduction of an aldehdye group into phenols, naphthols, and their ethers under special conditions into aromatic hydrocarbons and related compounds.

• From NCERT chemistry text book for class XII

Chapter 13 Amines. Page No 397. [Online view: http://www.iasexams.com/NCERT-Books/NCERTBooksforClass12/FreedownloadClass12Chemistry2NCERTBook/Class12_Chemistry2_Unit13_NCERT_TextBook_EnglishEdition.pdf]

Alternatively, chlorine or bromine can also be introduced in the benzene ring by treating the diazonium salt solution with corresponding halogen acid in the presence of copper powder. This is referred as Gatterman reaction.

The yield in Sandmeyer reaction is found to be better than Gattermann reaction.

Gattermann aldehyde synthesis.

• http://www.jergym.hiedu.cz/~canovm/mechanic/pravidl2/gatt/ga.htm says Gattermann aldehyde reaction is the preparation of phenolic aldehydes, phenol ethers or heterocyclic compounds by treatmenting aromatic substrate with hydrogen cyanide and hydrogen chloride in the presence of AlCl3 or ZnCl2.
• http://www.chempensoftware.com/reactions/RXN076.htm supporys the same

Those which says Gattermann synthesis is Gattermann aldehyde reaction.

• http://www.chem.ox.ac.uk/thirdyearcomputing/reactioninfo.asp?id=433

Those which points out Gattermann reaction is different from Gattermann aldehyde reaction.

• http://www.tutorvista.com/content/chemistry/chemistry-iv/organic-compounds/replacement-reactions.php
• http://www.textbooksonline.tn.nic.in/Books/12/Std12-Chem-EM-2.pdf

Need help from experts; please help Wikipedia to solve this mess. Gattermann reactions refer to two reactions - one with aldehydes and arenes; the other with diazonium salt. Valchemishnu^ʘ 19:44, 22 September 2011 (UTC)

• Why this hostility? Is this page in trouble? is it a mess? Do not bother us with cites from sources like tutorvista. March lists the Gattermann reaction twice , one as a formylation method and one as a halogenation method. There is even a Gattermann method itself (aryl dimerization). The formylation method takes place with zinc cyanide and HCl. HCN and zinc chloride can also be used. Therefore, on first inspection this article seems okay. We are aiming for constructive solutions when dealing with apparent inconsistencies V8rik (talk) 20:58, 22 September 2011 (UTC)

I agree that sites like tutorvista may not be used for verification. But what about NCERT textbook? This is a typical source for reference. And within Wikipedia, there are contradictions. That was given at the beginning of this discussion.

For clarification I am listing them

• Articles on Gattermann reaction and Gattermann aldehyde synthesis discuss same reaction but these are two separate articles.
• Wikipedia doesn't have an article on a name reaction (which I claimed Gattermann reaction) where Diazonium chloride is converted into haloarene in presence of copper powder and Halogen acid.
• A link to false page: At Nucleophilic_aromatic_substitution#Nucleophilic_aromatic_substitution_reactions the internal link must be discussing Gattermann reaction in which diazonium salt and Cu powders are there but here there is no such a discussion, rather it discusses another reaction.

And one more thing made me to say 'wikipedia in trouble'.

Gattermann-Skita synthesis redirects to pyridine's main page but is located only in a very small section and doesn't have its own article name space. (And to add more trouble problem (or whatever it is), List of organic reactions doesn't have Gattermann-Skita synthesis under the section G, but only at H.

I am convinced that the article says "It should not confused with the reaction where a diazonium salt is converted to an aryl halide by using copper powder and hydrochloric acid as opposed to using cuprous salt of the halide as in the Sandmeyer reaction. Although in some articles and books this reaction is also called Gatterman reaction". But is there any article on such a reaction? Then why does Nucleophilic_aromatic_substitution#Nucleophilic_aromatic_substitution_reactions have such an internal link?

• Please notice an internal link to Gattermann aldehyde synthesis in the Formylation reaction page where the former redirects to. Thus it creates a link to the same page itself!

Sorry if I am wrong, but please verify whether the information given are wrong or not. —Valchemishnu^ʘ 15:22, 23 September 2011 (UTC)

• • the Gattermann-Skita synthesis apparently is not notable to have a dedicated page or no one has yet been prepared to write the article . This is not "wikipedia in trouble". Countless reactions just get a mention on other pages. It is a good idea to move the content currently in Gattermann reaction to the Gattermann aldehyde synthesis V8rik (talk) 17:21, 26 September 2011 (UTC)

Merger proposal with Gattermann–Koch reaction

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result of this discussion was to Merge Project Osprey (talk) 16:26, 25 August 2014 (UTC)

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I propose that Gattermann–Koch reaction be merged into this article. They're essentially variants of the same process created by the same chemist. Most of the foreign language wiki's have these 2 reaction on the same page. There is also, for the purists amongst you, the options of doing the merger the other way around, as based on the current references the Gattermann–Koch reaction was created first. Project Osprey (talk) 11:07, 20 July 2014 (UTC)

Support merger, which will help unify the similarities and clarify the differences. It's the same Gattermann person, who extended/modified the original reaction he developed with Koch enough that this variant got its own name. I think Gattermann reaction is a better location for the article, given it's a name common to both (the article is more than just the Koch-related topic). In terms of wiki precedence, both were created at essentially the same time by the same editor, so neither is the "pre-existing" article. DMacks (talk) 19:01, 11 August 2014 (UTC)

Discussion has been running for over 30 days so I've going to push ahead with the merge. Project Osprey (talk) 16:26, 25 August 2014 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Why not phenol/phenol-ethers?

"However, unlike the Gattermann reaction with HCN, this reaction is not applicable to phenol and phenol ether substrates." with cite to Organic Reactions. I don't have access to this item at the moment. Could someone who does add a detail explaining what the problem is? For example, is it that the phenol O is too Lewis-basic and binds the metal, or by extension that the ether is cleaved by the acidic conditions? Or a totally different problem, with the aromatic ring being too electron-rich? Or...? DMacks (talk) 13:09, 24 September 2014 (UTC)

I don't have access either. I can see how phenol might react to give phenyl formate but I doubt that catalyst coordination is a problem... If the Org Syn prep is anything to go by you use a full molar equivalent of catalyst to do this. No idea why aryl ethers are a problem though. Project Osprey (talk) 14:03, 24 September 2014 (UTC)

Gatterman Reaction

It is the reaction of benzene dizonium salt with Copper powder and HCl and HBr to form Chlorobenzene and Bromobenzene respectively. 27.63.19.147 (talk) 04:03, 27 May 2022 (UTC)

That is a reaction sometimes called by this name, yes. It is linked in the hatnote at the top. DMacks (talk) 04:12, 27 May 2022 (UTC)