# Carboximidate > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Carboximidate > Markdown URL: https://mediated.wiki/source/Carboximidate.md > Source: https://en.wikipedia.org/wiki/Carboximidate > Source revision: 1337607423 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{more cn|date=August 2022}} 160px|thumb|right|The carboximidate group '''Carboximidates''' (or more general '''imidates''') are organic compounds, which can be thought of as [ester](/source/ester)s formed between an [imidic acid](/source/imidic_acid) ({{chem2|R\sC(\dNR′)OH}}) and an [alcohol](/source/Alcohol_(chemistry)), with the general formula {{chem2|R\sC(\dNR′)OR″}}. They are also known as '''imino ethers''', since they resemble [imine](/source/imine)s ({{chem2|>C\dN\s}}) with an oxygen atom connected to the carbon atom of the C=N double bond.{{Cite web |title=Pinner Reaction |url=https://www.organic-chemistry.org/namedreactions/pinner-reaction.shtm |access-date=2023-09-26 |website=Organic Chemistry Portal |publisher=Reto Mueller |place=Buckten, CH}} ==Synthesis== Imidates may be generated by a number of synthetic routes,{{cite journal|last=Roger|first=Robert|author2=Neilson, Douglas G.|title=The Chemistry of Imidates.|journal=[Chemical Reviews](/source/Chemical_Reviews)|date=1961|volume=61|issue=2|pages=179–211|doi=10.1021/cr60210a003}} but are in general formed by the [Pinner reaction](/source/Pinner_reaction). This proceeds via the acid catalyzed attack of nitriles by alcohols. thumb|center|500px|General mechanism of the Pinner reactionB. P. Mundy, M. G. Ellerd, F. G. Favaloro: ''Name Reactions and Reagents in organic Synthesis'', 2. Auflage, Wiley-Interscience, Hoboken, NJ '''2005''', {{ISBN|978-0-471-22854-7}}, S. 516. Imidates produced in this manner are formed as their hydrochloride salts, which are sometimes referred to as Pinner salts. Carboximidates are also formed as intermediates in the [Mumm rearrangement](/source/Mumm_rearrangement) and the [Overman rearrangement](/source/Overman_rearrangement). ==Imidate/amidate anions== An '''amidate/imidate''' anion is formed upon [deprotonation](/source/deprotonation) of an [amide](/source/amide) or [imidic acid](/source/imidic_acid). Since amides and imidic acids are [tautomers](/source/tautomers), they form the same anion upon deprotonation. The two names are thus synonyms describing the same anion, although arguably, imidate refers to the resonance contributor on the left, while amidate refers to the resonance contributor on the right. However, they are distinguished when they act as ligands for transition metals, with ''O-''bound species referred to as imidates and ''N''-bound species referred to as amidates. They can be considered aza-substituted analogues of [enolate](/source/enolate)s with the formula R-N=C(O−)R. center|180px|Imidate/amidate resonance ==Reactions== Carboximidates are good [electrophiles](/source/electrophiles) and undergo a range of addition reactions; with [aliphatic](/source/aliphatic) imidates generally reacting faster than [aromatic](/source/aromatic) imidates. They can be [hydrolyzed](/source/hydrolysis) to give [esters](/source/esters) and by an analogous process react with amines (including ammonia) to form [amidine](/source/amidine)s. Aliphatic imidates react with an excess of alcohol under acid catalysis to form [orthoester](/source/orthoester)s RC(OR)3, aromatic imidates can also be converted but far less readily. thumb|center|200px ===Chapman rearrangement=== {{Main|Chapman rearrangement}} The '''Chapman rearrangement''' is the thermal conversion of aryl ''N''-arylbenzimidates to the corresponding amides, via intramolecular migration of an aryl group from oxygen to nitrogen.{{Cite journal|author1=Schulenberg, J. W. |author2=Archer, S. |title=The Chapman Rearrangement|journal=[Organic Reactions](/source/Organic_Reactions)|year=1965|volume=14|pages=1–51 |doi=10.1002/0471264180.or014.01|isbn=0471264180}} It is named after [Arthur William Chapman](/source/Arthur_William_Chapman), who first described it,{{cite journal |last1=Chapman |first1=Arthur William |title=CCLXIX.—Imino-aryl ethers. Part III. The molecular rearrangement of ''N''-phenylbenziminophenyl ether |journal=J. Chem. Soc., Trans. |date=1925 |volume=127 |pages=1992–1998 |doi=10.1039/CT9252701992}} and is conceptually similar to the [Newman–Kwart rearrangement](/source/Newman%E2%80%93Kwart_rearrangement). center|300px|Chapman Rearrangement ===As a protecting group=== thumb|right|120px|Benzyl trichloroethanimidate Carboximidates can act as [protecting group](/source/protecting_group) for alcohols.{{cite book|last=Wuts|first=Peter G. M.|title=Protective groups in organic synthesis.|year=2006|publisher=WILEY|location=Hoboken, N.J.|isbn=978-0-471-69754-1|page=244|edition=4th|author2=Greene, Theodora W.}} For example, the base catalyzed reaction of [benzyl alcohol](/source/benzyl_alcohol) upon [trichloroacetonitrile](/source/trichloroacetonitrile) yields a [trichloroacetimidate](/source/trichloroacetimidate). This species has orthogonal stability to acetate and [TBS](/source/Tert-butyldimethylsilyl) protections and may be cleaved by acid hydrolysis.{{cite journal|last=Yu|first=Biao|author2=Yu, Hai |author3=Hui, Yongzheng |author4= Han, Xiuwen |title=Trichloroacetimidate as an Efficient Protective Group for Alcohols|journal=Synlett|date=June 1999|volume=1999|issue=6|pages=753–755|doi=10.1055/s-1999-2736}} ==See also== * [Amidines](/source/Amidines) * [Ester](/source/Ester)s * [Imidoyl chloride](/source/Imidoyl_chloride) — the "acyl chloride" variant * [Oxazoline](/source/Oxazoline) — the corresponding 5-membered heterocycle ==References== {{reflist}} Category:Carboximidates Category:Functional groups --- Adapted from the Wikipedia article [Carboximidate](https://en.wikipedia.org/wiki/Carboximidate) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Carboximidate?action=history)). 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