Difference between revisions of "Cycloocta-1,5-diene"
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==Reactions and applications== | ==Reactions and applications== | ||
===Organic reactions=== | ===Organic reactions=== | ||
| − | COD reacts with borane to give [[9-Borabicyclononane|9-borabicyclo[3.3.1]nonane]], commonly known as 9-BBN, a [[reagent]] in organic chemistry used in [[hydroboration]]s. COD adds SCl<sub>2</sub> (or similar reagents) to give 2,6-dichloro-9-thiabicyclo[3.3.1]nonane:<ref>{{OrgSynth | first = Roger | last = Bishop | title = 9-Thiabicyclo[3.3.1]nonane-2,6-dione | prep = CV9P0692 | volume = 70 | pages = 120 | year = 1992 | collvol = 9 | collvolpages = 692}}. {{citation | | + | COD reacts with borane to give [[9-Borabicyclononane|9-borabicyclo[3.3.1]nonane]], commonly known as 9-BBN, a [[reagent]] in organic chemistry used in [[hydroboration]]s. COD adds SCl<sub>2</sub> (or similar reagents) to give 2,6-dichloro-9-thiabicyclo[3.3.1]nonane:<ref>{{OrgSynth | first = Roger | last = Bishop | title = 9-Thiabicyclo[3.3.1]nonane-2,6-dione | prep = CV9P0692 | volume = 70 | pages = 120 | year = 1992 | collvol = 9 | collvolpages = 692}}. {{citation | first1 = David D. | last1 = Díaz | first2 = Antonella | last2 = Converso | first3 = K. B. | last3 = Sharpless | first4 = M. G. | last4 = Finn | title = 2,6-Dichloro-9-thiabicyclo[3.3.1]nonane: Multigram Display of Azide and Cyanide Components on a Versatile Scaffold | journal = Molecules | year = 2006 | volume = 11 | pages = 212–18| doi = 10.3390/11040212}}.</ref> |
[[Image:CODSCl2.png|center|400px|2,6-Dichloro-9-thiabicyclo[3.3.1]nonane, synthesis and reactions]] | [[Image:CODSCl2.png|center|400px|2,6-Dichloro-9-thiabicyclo[3.3.1]nonane, synthesis and reactions]] | ||
The resulting dichloride can be further modified as the di-[[azide]] or di-[[cyano]] derivative in a [[nucleophilic substitution]] aided by [[anchimeric assistance]]. | The resulting dichloride can be further modified as the di-[[azide]] or di-[[cyano]] derivative in a [[nucleophilic substitution]] aided by [[anchimeric assistance]]. | ||
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:[[Image:M(cod)2.png|thumb|150px|right|Structure of M(cod)<sub>2</sub> for M = Ni, Pd, Pt.]] | :[[Image:M(cod)2.png|thumb|150px|right|Structure of M(cod)<sub>2</sub> for M = Ni, Pd, Pt.]] | ||
| − | Ni(cod)<sub>2</sub> is prepared by reduction of [[anhydrous]] nickel [[acetylacetonate]] in the presence of the ligand, using [[triethylaluminium]].<ref>{{citation | last1 = Schunn | | + | Ni(cod)<sub>2</sub> is prepared by reduction of [[anhydrous]] nickel [[acetylacetonate]] in the presence of the ligand, using [[triethylaluminium]].<ref>{{citation | first1 = R. A. | last1 = Schunn | first2 = S. D. | last2 = Ittel | first3 = M. A. | last3 = Cushing | first4 = R. | last4 = Baker | first5 = R. J. | last5 = Gilbert | first6 = D. P. | last6 = Madden | title = Bis(1,5-Cyclooctadiene)Nickel(0) | journal = Inorg. Synth. | volume = 28 | year = 1990 | pages = 94 | doi = 10.1002/9780470132593.ch25}}.</ref> |
:1/3[Ni(C<sub>5</sub>H<sub>7</sub>O<sub>2</sub>)<sub>2</sub>]<sub>3</sub> + 2COD + 2Al(C<sub>2</sub>H<sub>5</sub>)<sub>3</sub> → Ni(cod)<sub>2</sub> + 2Al(C<sub>2</sub>H<sub>5</sub>)<sub>2</sub>(C<sub>5</sub>H<sub>7</sub>O<sub>2</sub>) + C<sub>2</sub>H<sub>4</sub> + C<sub>2</sub>H<sub>6</sub> | :1/3[Ni(C<sub>5</sub>H<sub>7</sub>O<sub>2</sub>)<sub>2</sub>]<sub>3</sub> + 2COD + 2Al(C<sub>2</sub>H<sub>5</sub>)<sub>3</sub> → Ni(cod)<sub>2</sub> + 2Al(C<sub>2</sub>H<sub>5</sub>)<sub>2</sub>(C<sub>5</sub>H<sub>7</sub>O<sub>2</sub>) + C<sub>2</sub>H<sub>4</sub> + C<sub>2</sub>H<sub>6</sub> | ||
| − | The related Pt(cod)<sub>2</sub> is prepared by a more circuitous route involving the dilithium [[cyclooctatetraene]]:<ref>{{citation | last1 = Crascall | | + | The related Pt(cod)<sub>2</sub> is prepared by a more circuitous route involving the dilithium [[cyclooctatetraene]]:<ref>{{citation | first1 = Louise E. | last1 = Crascall | first2 = John L. | last2 = Spencer | first3 = Ruth Ann | last3 = Doyle | first4 = Robert J. | last4 = Angelici | title = Olefin Complexes of Platinum | journal = Inorg. Synth. | year = 1990 | volume = 28 | pages = 126 | doi = 10.1002/9780470132593.ch34}}.</ref> |
:Li<sub>2</sub>C<sub>8</sub>H<sub>8</sub> + PtCl<sub>2</sub>(cod) + 3C<sub>7</sub>H<sub>10</sub> → [Pt(C<sub>7</sub>H<sub>10</sub>)<sub>3</sub>] + 2LiCl + C<sub>8</sub>H<sub>8</sub> + C<sub>8</sub>H<sub>12</sub> | :Li<sub>2</sub>C<sub>8</sub>H<sub>8</sub> + PtCl<sub>2</sub>(cod) + 3C<sub>7</sub>H<sub>10</sub> → [Pt(C<sub>7</sub>H<sub>10</sub>)<sub>3</sub>] + 2LiCl + C<sub>8</sub>H<sub>8</sub> + C<sub>8</sub>H<sub>12</sub> | ||
:Pt(C<sub>7</sub>H<sub>10</sub>)<sub>3</sub> + 2COD → Pt(cod)<sub>2</sub> + 3C<sub>7</sub>H<sub>10</sub> | :Pt(C<sub>7</sub>H<sub>10</sub>)<sub>3</sub> + 2COD → Pt(cod)<sub>2</sub> + 3C<sub>7</sub>H<sub>10</sub> | ||
Revision as of 21:46, 23 August 2009
| 1,5-Cyclooctadiene | |
|---|---|
 |
 |
| Identifiers | |
| InChI | InChI=1/C8H12/c1-2-4-6-8-7-5-3-1/h1-2,7-8H,3-6H2/b2-1-,8-7- |
| InChIKey | VYXHVRARDIDEHS-QGTKBVGQBM |
| Standard InChI | InChI=1S/C8H12/c1-2-4-6-8-7-5-3-1/h1-2,7-8H,3-6H2/b2-1-,8-7- |
| Standard InChIKey | VYXHVRARDIDEHS-QGTKBVGQSA-N |
| CAS number | [] |
| EC number | |
| ChemSpider | |
| Properties | |
| Chemical formula | C8H12 |
| Molar mass | 108.18 g/mol |
| Appearance | colorless liquid |
| Density | 0.882 g/ml, liquid |
| Melting point |
-69.5 °C |
| Boiling point |
151 °C |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
1,5-Cyclooctadiene is the organic compound with the chemical formula C8H12. Generally abbreviated COD, this diene is a useful precursor to other organic compounds and serves as a ligand in organometallic chemistry.[1][2]
Contents
Synthesis
1,5-Cyclooctadiene can be prepared by dimerization of butadiene in the presence of a nickel catalyst, a coproduct being vinylcyclohexene. Approximately 10,000 tons were produced in 2005.[3]
Reactions and applications
Organic reactions
COD reacts with borane to give 9-borabicyclo[3.3.1]nonane, commonly known as 9-BBN, a reagent in organic chemistry used in hydroborations. COD adds SCl2 (or similar reagents) to give 2,6-dichloro-9-thiabicyclo[3.3.1]nonane:[4]
![2,6-Dichloro-9-thiabicyclo[3.3.1]nonane, synthesis and reactions](/wikichem/index.php/File:CODSCl2.png)
The resulting dichloride can be further modified as the di-azide or di-cyano derivative in a nucleophilic substitution aided by anchimeric assistance.
Metal complexes
1,5-COD typically binds to low-valence metals via both alkene groups. The complex Ni(cod)2 is a precursor to several nickel(0) and Ni(II) complexes. Metal-COD complexes are attractive because they are sufficiently stable to be isolated, often being more robust than related ethylene complexes. The stability of COD complexes is attributable to the chelate effect. The COD ligands are easily displaced by other ligands, such as phosphines.
2.png)
Ni(cod)2 is prepared by reduction of anhydrous nickel acetylacetonate in the presence of the ligand, using triethylaluminium.[5]
- 1/3[Ni(C5H7O2)2]3 + 2COD + 2Al(C2H5)3 → Ni(cod)2 + 2Al(C2H5)2(C5H7O2) + C2H4 + C2H6
The related Pt(cod)2 is prepared by a more circuitous route involving the dilithium cyclooctatetraene:[6]
- Li2C8H8 + PtCl2(cod) + 3C7H10 → [Pt(C7H10)3] + 2LiCl + C8H8 + C8H12
- Pt(C7H10)3 + 2COD → Pt(cod)2 + 3C7H10
Extensive work has been reported on complexes of COD, much of which can has been described in volumes 25, 26, and 28 of Inorganic Syntheses. The platinum complex has been used in many syntheses:
- Pt(cod)2 + 3 C2H4 → Pt(C2H4)3 + 2COD
COD complexes are useful as starting materials, one noteworthy example is the reaction:
- Ni(cod)2 + 4CO ⇌ Ni(CO)4 + 2COD
The product Ni(CO)4 is highly toxic, thus it is advantageous to generate it in the reaction vessel as opposed to being dispensed directly. Other low-valent metal complexes of COD include Mo(cod)(CO)4, [RuCl2(cod)]n, and Fe(cod)(CO)3. COD is an especially important in the coordination chemistry of rhodium(I) and iridium(I), examples being Crabtree's catalyst and cyclooctadiene rhodium chloride dimer. The square planar complexes [M(cod)2]+ are known (M = Rh, Ir).
References
- ↑ Buehler, C.; Pearson, D. Survey of Organic Syntheses; Wiley-Interscience: New York, 1970.
- ↑ Shriver, Deward F.; Atkins, Peter W. Inorganic Chemistry; W. H. Freeman: New York, 1999.
- ↑ Schiffer, Thomas; Oenbrink, Georg Cyclododecatriene, Cyclooctadiene, and 4-Vinylcyclohexene. In Ullmann’s Encyclopedia of Industrial Chemistry; Wiley-VCH: Weinheim, 2005.
- ↑ Bishop, Roger 9-Thiabicyclo[3.3.1]nonane-2,6-dione. Org. Synth. 1992, 70, 120, <http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV9P0692>; Coll. Vol., 9, 692. Díaz, David D.; Converso, Antonella; Sharpless, K. B.; Finn, M. G. 2,6-Dichloro-9-thiabicyclo[3.3.1]nonane: Multigram Display of Azide and Cyanide Components on a Versatile Scaffold. Molecules 2006, 11, 212–18. DOI: 10.3390/11040212.
- ↑ Schunn, R. A.; Ittel, S. D.; Cushing, M. A.; Baker, R.; Gilbert, R. J.; Madden, D. P. Bis(1,5-Cyclooctadiene)Nickel(0). Inorg. Synth. 1990, 28, 94. DOI: 10.1002/9780470132593.ch25.
- ↑ Crascall, Louise E.; Spencer, John L.; Doyle, Ruth Ann; Angelici, Robert J. Olefin Complexes of Platinum. Inorg. Synth. 1990, 28, 126. DOI: 10.1002/9780470132593.ch34.
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