Tetramethylethylene

{{Chembox | ImageFile1 = Me4C2.svg | ImageSize1 = 124 px | ImageFile2 = Tetramethylethylene-3D-balls.png | ImageSize2 = | ImageAlt = | PIN = 2,3-Dimethylbut-2-ene | OtherNames = |Section1={{Chembox Identifiers | CASNo = 563-79-1 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 7UQ4B3F5JC | PubChem = 11250 | ChemSpiderID = 10776 | EC_number = 209-263-8 | StdInChI=1S/C6H12/c1-5(2)6(3)4/h1-4H3 | StdInChIKey = WGLLSSPDPJPLOR-UHFFFAOYSA-N | SMILES = CC(=C(C)C)C }} |Section2={{Chembox Properties | C=6|H=12 | MolarMass = | Appearance = colorless liquid | Density = 0.7075 g/cm³ (20&nbsp;°C) | MeltingPtC = -74.6 | BoilingPtC = 73.3 | CriticalTP = {{val|521.0|(9)|u=K}}, {{val|3.4|(1)|u=MPa}}<ref name="CRC97"/> | Solubility = insoluble | SolubleOther = soluble in ethanol, ether, acetone, chloroform<ref name="CRC97"/> | RefractIndex = 1.4122 (20&nbsp;°C)<ref name="CRC97">{{Cite book |title=CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data. |date=2016 |others=William M. Haynes, David R. Lide, Thomas J. Bruno |isbn=978-1-4987-5428-6 |edition=2016-2017, 97th |location=Boca Raton, Florida |oclc=930681942}}</ref> | MagSus = {{val|-65.9e-6}}&nbsp;cm³·mol⁻¹<ref name="CRC97"/> }} | Section4 = {{Chembox Thermochemistry | Thermochemistry_ref = <ref name="CRC97"/> | HeatCapacity = 174.7&nbsp;J·mol⁻¹·K⁻¹ | Entropy = 270.2&nbsp;J·mol⁻¹·K⁻¹ | DeltaHform = −101.4&nbsp;kJ·mol⁻¹ (liquid)<br />−68.1&nbsp;kJ·mol⁻¹ (gas) | DeltaGfree = | DeltaHcombust = | DeltaHfus = 6.45&nbsp;kJ·mol⁻¹ (at melting point) | DeltaHvap = 32.51&nbsp;kJ·mol⁻¹ (25&nbsp;°C)<br />29.64&nbsp;kJ·mol⁻¹ (at boiling point) | DeltaHsublim = }} |Section7={{Chembox Hazards | GHSPictograms = {{GHS02}}{{GHS08}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|225|304}} | PPhrases = {{P-phrases|210|233|240|241|242|243|280|301+310|303+361+353|331|370+378|403+235|405|501}} | MainHazards = | FlashPt = −8&nbsp;°C | AutoignitionPt = 401&nbsp;°C<ref name="CRC97"/> }} }}

'''Tetramethylethylene''' is a hydrocarbon with the formula Me₂C=CMe₂ (Me = methyl). A colorless liquid, it is the simplest tetrasubstituted alkene.

==Synthesis== It can be prepared by base-catalyzed isomerization of 2,3-dimethyl-1-butene.<ref>{{cite journal|doi=10.1016/S0926-860X(01)00839-0|title=Solid base catalysts: Generation of basic sites and application to organic synthesis|journal=Applied Catalysis A: General|volume=222|issue=1–2|pages=247–259|year=2001|last1=Hattori|first1=Hideshi |bibcode=2001AppCA.222..247H }}</ref> Another route involves direct dimerization of propylene.<ref name=cat>{{cite journal |doi=10.1021/acs.chemrev.0c00076|title=Nickel Catalyzed Olefin Oligomerization and Dimerization |year=2020 |last1=Olivier-Bourbigou |first1=H. |last2=Breuil |first2=P. A. R. |last3=Magna |first3=L. |last4=Michel |first4=T. |last5=Espada Pastor |first5=M. Fernandez |last6=Delcroix |first6=D. |journal=Chemical Reviews |volume=120 |issue=15 |pages=7919–7983 |pmid=32786672 |s2cid=221124789 |url=https://hal-ifp.archives-ouvertes.fr/hal-02954532/file/Nickel%20Catalyzed%20Olefin.pdf }}</ref> It can also be produced by photolysis of tetramethylcyclobutane-1,3-dione.<ref>{{cite journal |doi=10.15227/orgsyn.047.0034|title=Cyclohexylidenecyclohexane |journal=Organic Syntheses |year=1967 |volume=47 |page=34|author=Nicholas J. Turro, Peter A. Leermakers, George F. Vesley }}</ref>

==Reactions== Tetramethylethylene forms metal-alkene complexes with low-valent metals and reacts with diborane to give the monoalkyborane known as thexylborane.<ref>{{cite journal|title=Thexylborane-A Highly Versatile Reagent for Organic Synthesis via Hydroboration|journal=Synthesis|volume=1974|issue=2|pages=77–89|year=1974|last1=Negishi|first1=Ei-Ichi|last2=Brown|first2=Herbert C.|doi=10.1055/s-1974-23248|s2cid=96012955 }}</ref><ref>{{cite book|doi=10.1002/9780470132593.ch22|title=Di-μ-Chloro-Bis(η⁴-1,5-Cyclooctadiene)-Dirhodium(I)|series=Inorganic Syntheses|pages=88–90|year=1990|volume=28|last1=Giordano|first1=G.|last2=Crabtree|first2=R. H.|chapter=Di-μ-Chloro-Bis(η ⁴ -1,5-Cyclooctadiene)-Dirhodium(I) |isbn=9780471526193 }}</ref>

Oxidation gives pinacol.

It is a precursor to the herbicide fenpropathrin.<ref name=cat/>

==References== <references />

Category:Alkenes