Norbornene: Difference between revisions

{{Chembox

|Verifiedfields = changed

|Watchedfields = changed

|verifiedrevid = 450599059

|Reference = <ref>[https://fscimage.fishersci.com/msds/66955.htm Norbornene MSDS]</ref>

|ImageFileL1 = Norbornene.png

|ImageFileR1 = Norbornene2.png

|ImageFile2 = Norbornene3.png

|ImageSize2 = 150px

|PIN = Bicyclo[2.2.1]hept-2-ene <!-- Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) -->

|OtherNames = Norbornylene<br>Norcamphene

|Section1={{Chembox Identifiers

|PubChem = 10352

|ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

|ChemSpiderID = 9925

|InChI = 1/C7H10/c1-2-7-4-3-6(1)5-7/h1-2,6-7H,3-5H2

|InChIKey = JFNLZVQOOSMTJK-UHFFFAOYAB

|StdInChI_Ref = {{stdinchicite|changed|chemspider}}

|StdInChI = 1S/C7H10/c1-2-7-4-3-6(1)5-7/h1-2,6-7H,3-5H2

|StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

|StdInChIKey = JFNLZVQOOSMTJK-UHFFFAOYSA-N

|CASNo_Ref = {{cascite|correct|CAS}}

|CASNo = 498-66-8

|UNII_Ref = {{fdacite|correct|FDA}}

|UNII = 2Q51FLS550

|EINECS = 207-866-0

|SMILES = C1=CC2CCC1C2

|ChEBI_Ref = {{ebicite|correct|EBI}}

|ChEBI = 52286

|KEGG_Ref = {{keggcite|correct|kegg}}

}}

|Section2={{Chembox Properties

| C=7 | H=10

|Appearance = White solid

|MeltingPtC = 42 to 46

|BoilingPtC = 96

}}

|Section7={{Chembox Hazards

|NFPA-H = 2

|NFPA-F = 3

|NFPA-R = 1

|NFPA-S =

|FlashPtC = −15

}}

|Section8={{Chembox Related

|OtherCompounds = [[Nadic anhydride]]

}}

'''Norbornene''' or '''norbornylene''' or '''norcamphene''' is a highly strained bridged cyclic [[hydrocarbon]]. It is a white solid with a pungent sour odor. The [[molecule]] consists of a [[cyclohexene]] ring with a [[methylene bridge]] between carbons 1 and 4. The molecule carries a [[double bond]] which induces significant [[ring strain]] and significant reactivity.

==Production==

Norbornene is made by a [[Diels–Alder reaction]] of [[cyclopentadiene]] and [[ethylene]]. Many substituted norbornenes can be prepared similarly.<ref>{{OrgSynth | first1= Paul |last1=Binger |first2=Petra |last2=Wedemann |first3=Udo H. |last3=Brinker| title = Cyclopropene: A New Simple Synthesis and its Diels-Alder Reaction with Cyclopentadiene | collvol = 10 | collvolpages = 231 | prep=v77p0254}}</ref><ref>{{OrgSynth | first1=Masaji |last1=Oda |first2=Takeshi |last2=Kawase |first3=Tomoaki |last3=Okada |first4=Tetsuya |last4=Enomoto | title = 2-Cyclohexene-1,4-dione | collvol = 9 | collvolpages = 186 | prep = cv9p0186}}</ref> Related bicyclic compounds are [[norbornadiene]], which has the same carbon skeleton but with two double bonds, and [[norbornane]] which is prepared by [[hydrogenation]] of norbornene.

== Reactions ==

Norbornene undergoes an acid-catalyzed [[hydration reaction]] to form [[norborneol]]. This reaction was of great interest in the elucidation of the [[2-Norbornyl cation|non-classical carbonion controversy]].

Norbornene is used in the [[Catellani reaction]] and in norbornene-mediated ''meta''-C−H activation.<ref>{{cite journal|last=Thansandote|first=Praew|date=21 May 2010|title=Palladium-Catalyzed Domino C−C/C−N Coupling Using a Norbornene Template: Synthesis of Substituted Benzomorpholines, Phenoxazines, and Dihydrodibenzoxazepines|journal=The Journal of Organic Chemistry|volume=75|issue=10|pages=3495–3498|doi=10.1021/jo100408p|pmid=20423091|last2=Chong|first2=Eugene|last3=Feldmann|first3=Kai-Oliver|last4=Lautens|first4=Mark}}</ref>

Certain substituted norbornenes undergo unusual substitution reactions owing to the generation of the [[2-Norbornyl cation|2-norbornyl cation]].

Being a strained ene, norbornenes react readily with [[thiol]]s in the [[thiol-ene reaction]] to form [[thioether]]s. This makes norbornene-functionalized monomers ideal for polymerization with thiol-based monomers to form thiol-ene networks.<ref>{{cite journal |last1=Hoyle |first1=Charles E. |last2=Bowman |first2=Christopher N. |title=Thiol–Ene Click Chemistry |journal=[[Angewandte Chemie International Edition]] |year=2010 |volume=49 |issue=9 |doi=10.1002/anie.200903924 |pages=1540–1573}}</ref>

===Polynorbornenes===

Norbornenes are important [[monomer]]s in [[ring-opening metathesis polymerization]]s (ROMP). Typically these conversions are effected with ill-defined catalysts. '''Polynorbornenes''' exhibit high [[glass transition temperature]]s and high optical clarity.<ref name=KO>{{cite encyclopedia|encyclopedia=Kirk-Othmer Encyclopedia of Chemical Technology|first1=Lionel |last1=Delaude |first2=Alfred F. |last2=Noels|year=2005| doi=10.1002/0471238961.metanoel.a01|place=Weinheim|publisher=Wiley-VCH|isbn = 978-0471238966|chapter = Metathesis}}</ref>

:[[File:Polynbornene.png|thumb|center|444px|ROMP reaction giving polynorbornene. Like most commercial alkene metathesis processes, this reaction does not employ a well-defined molecular catalyst.]]

In addition to ROMP, norbornene monomers also undergo vinyl-[[addition polymerization]], and is a popular monomer for use in [[cyclic olefin copolymer]]s.

Polynorbornene is used mainly in the rubber industry for antivibration (rail, building, industry), antiimpact (personal protective equipment, shoe parts, bumpers) and grip improvement (toy tires, racing tires, transmission systems, transports systems for copiers, feeders, etc.)

[[Ethylidene norbornene]] is a related monomer derived from [[cyclopentadiene]] and [[butadiene]].

==See also==

*[[Nadic anhydride]]

{{Reflist|30em}}

{{Authority control}}

[[Category:Monomers]]

[[Category:Norbornanes]]