| Revision as of 12:04, 6 December 2011 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Saving copy of the {{chembox}} taken from revid 456864551 of page Pyridinium_chlorochromate for the Chem/Drugbox validation project (updated: 'ChemSpiderID', 'StdInChI', 'StdInChIKey', 'CASNo'). |
Latest revision as of 18:59, 14 July 2024 edit Gammahedron (talk | contribs)53 editsm minor changes of English language |
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{{Chembox |
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{{ambox | text = This page contains a copy of the infobox ({{tl|chembox}}) taken from revid of page ] with values updated to verified values.}} |
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|Verifiedfields = changed |
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{{chembox |
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|Watchedfields = changed |
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| verifiedrevid = 406365741 |
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|verifiedrevid = 464376959 |
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| Name = Pyridinium chlorochromate |
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|Name = Pyridinium chlorochromate |
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| ImageFile = Pyridinium_chlorochromate.PNG |
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|ImageFile = Corey-Reagenz.svg |
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| ImageSize = 150px |
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|ImageSize = 150px |
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| ImageName = Chemical structure of the Pyridinium Chlorochromate |
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|ImageName = Chemical structure of pyridinium chlorochromate |
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| ImageFileL1 = Pyridinium-3D-balls.png |
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|ImageFileL1 = Pyridinium-3D-balls.png |
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| ImageNameR1 = Ball-and-stick model of the pyridinium cation |
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|ImageNameL1 = Ball-and-stick model of the pyridinium cation |
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| ImageFileR1 = Chlorochromate-3D-balls.png |
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|ImageFileR1 = Chlorochromate-3D-balls.png |
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| ImageNameR1 = Ball-and-stick model of the chlorochromate anion |
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| IUPACName = Pyridinium chlorochromate |
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|ImageNameR1 = Ball-and-stick model of the chlorochromate anion |
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|IUPACName = Pyridinium chlorochromate |
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| OtherNames = PCC |
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|OtherNames = PCC; Corey-Suggs reagent |
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| Section1 = {{Chembox Identifiers |
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|Section1={{Chembox Identifiers |
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| InChI = 1/C5H5N.ClH.Cr.3O/c1-2-4-6-5-3-1;;;;;/h1-5H;1H;;;;/q;;+1;;;-1/rC5H5N.ClCrO3/c1-2-4-6-5-3-1;1-2(3,4)5/h1-5H;/q;-1/p+1 |
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|CASNo_Ref = {{cascite|correct|CAS}} |
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| InChIKey = LEHBURLTIWGHEM-YOEUSAHMAN |
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| CASNo = <!-- blanked - oldvalue: 26299-14-9 --> |
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|CASNo = 26299-14-9 |
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|EINECS = 247-595-5 |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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|UNII_Ref = {{fdacite|correct|FDA}} |
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| ChemSpiderID = 21106468 |
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|UNII = DTV5HU1N27 |
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| SMILES = O=(=O)()Cl.1ccccc1 |
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|ChEBI = 176795 |
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| StdInChI_Ref = {{stdinchicite|correct|chemspider}} |
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|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| StdInChI = 1S/C5H5N.ClH.Cr.3O/c1-2-4-6-5-3-1;;;;;/h1-5H;1H;;;;/q;;-2;;;-1 |
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|ChemSpiderID = 10608386 |
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| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |
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|PubChem = 129695875 |
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| StdInChIKey = YCSAHNCILFTDEP-UHFFFAOYSA-N |
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|SMILES = C1=CC=C=C1.(=O)(=O)Cl |
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|StdInChI_Ref = {{stdinchicite|changed|chemspider}} |
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|StdInChI = 1S/C5H5N.ClH.Cr.3O/c1-2-4-6-5-3-1;;;;;/h1-5H;1H;;;;/q;;+1;;;-1 |
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|StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} |
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|StdInChIKey = LEHBURLTIWGHEM-UHFFFAOYSA-N |
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|InChI = 1/C5H5N.ClH.Cr.3O/c1-2-4-6-5-3-1;;;;;/h1-5H;1H;;;;/q;;+1;;;-1/rC5H5N.ClCrO3/c1-2-4-6-5-3-1;1-2(3,4)5/h1-5H;/q;-1/p+1 |
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|InChIKey = LEHBURLTIWGHEM-YOEUSAHMAN |
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}} |
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}} |
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| Section2 = {{Chembox Properties |
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|Section2={{Chembox Properties |
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| Formula = C<sub>5</sub>H<sub>5</sub>NHClCrO<sub>3</sub> |
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|Formula = C<sub>5</sub>H<sub>6</sub>ClCrNO<sub>3</sub> |
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| MolarMass = 215.56 g/mol |
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|MolarMass = 215.56 g/mol |
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|Appearance = yellow-orange solid<ref name=eEROS>{{cite encyclopedia |last1=Piancatelli |first1= G. |last2=Luzzio |first2=F. A. |encyclopedia=e-EROS Encyclopedia of Reagents for Organic Synthesis |title=Pyridinium Chlorochromate |year=2007 |publisher=John Wiley & Sons |doi=10.1002/9780470842898.rp288.pub2|isbn= 978-0471936237}}</ref> |
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| Appearance = orange crystalline powder |
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| MeltingPtC = 205 |
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|MeltingPtC = 205 |
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|SolubleOther = soluble in ], ], ] |
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| Solvent = other solvents |
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|Solvent = other solvents |
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| SolubleOther = soluble in ],<br />], ],<br />], ],<br />] |
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}} |
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| Section7 = {{Chembox Hazards |
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| ExternalMSDS = |
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| MainHazards = oxidizing, toxic, flammable<br />carcinogenic, irritant |
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| NFPA-H = 3 | NFPA-R = 3 | NPFA-F = 0 |
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| RPhrases = {{R49}}, {{R8}}, {{R43}}, {{R50/53}} |
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| SPhrases = {{S53}}, {{S45}}, {{S60}}, {{S61}} |
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}} |
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}} |
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|Section7={{Chembox Hazards |
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|ExternalSDS = |
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|GHSPictograms = {{GHS03}}{{GHS08}}{{GHS07}}{{GHS09}} |
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|GHSSignalWord = Danger |
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|HPhrases = {{H-phrases|272|317|350|410}} |
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|PPhrases = {{P-phrases|201|280|273|221|308+313|302+352}} |
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|MainHazards = Toxic, oxidizer, carcinogenic, strong environmental pollutant |
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|NFPA-H = 2 |
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|NFPA-F = 1 |
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|NFPA-R = 2 |
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|NFPA-S = OX |
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|NFPA_ref = <ref>{{cite web |url=http://www.acros.com/Ecommerce/msds.aspx?PrdNr=18367&Country=US&Language=en |title=Safety Data Sheet |year=2015 |website=Acros Organics |access-date=2016-06-10}}</ref> |
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}} |
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}} |
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}} |
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] |
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'''Pyridinium chlorochromate''' ('''PCC''') is a yellow-orange ] with the ] <sup>+</sup><sup>−</sup>. It is a ] in ] used primarily for ] of ]s to form ]s. A variety of related compounds are known with similar reactivity. PCC offers the advantage of the selective oxidation of alcohols to aldehydes or ketones, whereas many other reagents are less selective.<ref name=eEROS /> |
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==Structure and preparation== |
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PCC consists of a ] cation, <sup>+</sup>, and a tetrahedral chlorochromate anion, <sup>−</sup>. Related salts are also known, such as 1-butylpyridinium chlorochromate, and ]. |
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PCC is commercially available. ],<ref>{{cite web |url=https://www.science.org/content/blog-post/old-stuff |title=The Old Stuff |last=Lowe |first=Derek |author-link=Derek Lowe (chemist) |website=In The Pipeline |publisher=Science |access-date=2015-11-21}}</ref> the reagent was originally prepared via addition of ] into a cold solution of ] in concentrated ]:<ref name=corey>{{cite journal |last1=Corey |first1=E. J. |last2=Suggs |first2=J. W. |year=1975 |title=Pyridinium Chlorochromate. An Efficient Reagent for Oxidation of Primary and Secondary Alcohols to Carbonyl Compounds |journal=] |volume=16 |issue=31 |pages=2647–2650 |doi=10.1016/S0040-4039(00)75204-X}}</ref> |
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:C<sub>5</sub>H<sub>5</sub>N + HCl + CrO<sub>3</sub> → |
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In one alternative method, formation of toxic ] (CrO<sub>2</sub>Cl<sub>2</sub>) fumes during the making of the aforementioned solution were minimized by simply changing the order of addition: a cold solution of pyridine in concentrated hydrochloric acid was added to solid chromium trioxide under stirring.<ref>{{cite journal |last1=Agarwal |first1=S. |last2=Tiwari |first2=H. P. |last3=Sharma |first3=J. P. |year=1990 |title=Pyridinium Chlorochromate: An Improved Method for Its Synthesis and Use of Anhydrous Acetic Acid as Catalyst for Oxidation Reactions |journal=] |volume=46 |issue=12 |pages=4417–4420 |doi=10.1016/S0040-4020(01)86776-4}}</ref> |
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==Uses== |
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===Oxidation of alcohols=== |
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PCC is used as an ]. In particular, it has proven to be highly effective in ] to ]s and ]s, respectively. The reagent is more selective than the related ], so there is little chance of over-oxidation to form ]s if acidified ] is used as long as water is not present in the reaction mixture. A typical PCC oxidation involves addition of an alcohol to a suspension of PCC in ].<ref>{{OrgSynth | author = Paquette, L. A. | author2 = Earle, M. J. | author3 = Smith, G. F. | year = 1996 | title = (4''R'')-(+)-''tert''-Butyldimethylsiloxy-2-cyclopenten-1-one | volume = 73 | pages = 36 | prep = cv9p0132 | collvol = 9 | collvolpages = 132}}</ref><ref>{{OrgSynth | author = Tu, Y. | author2 = Frohn, M. | author3 = Wang, Z.-X. | author4 = Shi, Y. | year = 2003 | title = Synthesis of 1,2:4,5-Di-''O''-isopropylidene-D-erythro-2,3-hexodiulo-2,6-pyranose. A Highly Enantioselective Ketone Catalyst for Epoxidation | volume = 80 | pages = 1 | prep = v80p0001}}</ref><ref>{{OrgSynth | author = White, J. D. | author2 = Grether, U. M. | author3 = Lee, C.-S. | year = 2005 | title = (''R'')-(+)-3,4-Dimethylcyclohex-2-en-1-one | volume = 82 | pages = 108 | prep = v82p0108 | collvol = 11 | collvolpages = 100}}</ref> The general reaction is: |
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:2 + 3 R<sub>2</sub>CHOH → 2 Cl + Cr<sub>2</sub>O<sub>3</sub> + 3 R<sub>2</sub>C=O + 3 H<sub>2</sub>O |
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For example, the ] ] was oxidized to ]:<ref>{{cite journal |last1=Lao |first1=A. |last2=Fujimoto |first2=Y. |last3=Tatsuno |first3=T. |year=1984 |title=Studies on the Constituents of ''Artemisia argyi'' Lévl & Vant |url=https://www.jstage.jst.go.jp/article/cpb1958/32/2/32_2_723/_article |journal=] |volume=32 |issue=2 |pages=723–727 |doi=10.1248/cpb.32.723 |access-date=2016-06-05|doi-access=free }}</ref> |
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:] |
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=== Babler oxidation === |
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{{main|Babler oxidation}} |
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With tertiary alcohols, the ] formed from PCC can isomerize ''via'' a -sigmatropic reaction]] and following oxidation yield an enone, in a reaction known as the Babler oxidation: |
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] |
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This type of oxidative transposition reaction has been synthetically utilized, ''e.g.'' for the synthesis of ].<ref>{{Cite journal|last=Killoran|first=Patrick M.|last2=Rossington|first2=Steven B.|last3=Wilkinson|first3=James A.|last4=Hadfield|first4=John A.|date=2016|title=Expanding the scope of the Babler–Dauben oxidation: 1,3-oxidative transposition of secondary allylic alcohols|url=https://linkinghub.elsevier.com/retrieve/pii/S0040403916309340|journal=Tetrahedron Letters|language=en|volume=57|issue=35|pages=3954–3957|doi=10.1016/j.tetlet.2016.07.076}}</ref> |
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Using other common oxidants in the place of PCC usually leads to dehydration, because such alcohols cannot be oxidized directly. |
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=== Other reactions === |
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PCC also converts suitable unsaturated alcohols and aldehydes to ]s. This pathway, an oxidative ]ic cyclization, is illustrated by the conversion of (−)-] to (−)-]. |
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PCC also effects ], for example, in conversion of ]s to ]s.<ref name="eEROS" /> |
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==Related reagents== |
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Other more convenient or less toxic reagents for oxidizing ]s include ], which is used in ] and ] oxidations, and ], such as the ]. |
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==Safety== |
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One disadvantage to the use of PCC is its toxicity, which it shares with other ] compounds. |
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==See also== |
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*] |
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==References== |
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{{Reflist}} |
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==Further reading== |
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* {{cite book |last1=Tojo |first1=G. |last2=Fernández |first2=M. |year=2006 |editor-last=Tojo |editor-first=G. |title=Oxidation of Alcohols to Aldehydes and Ketones: A Guide to Current Common Practice |series=Basic Reactions in Organic Synthesis |location=New York |publisher=] |isbn=978-0-387-23607-0}} |
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==External links== |
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{{Chromates and dichromates}} |
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{{Chromium compounds}} |
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] |
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] |
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] |
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] |