Nitroethylene
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Preferred IUPAC name
Nitroethene | |
Identifiers | |
3D model (
JSmol ) |
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1209274 | |
ChEBI | |
ChemSpider | |
130431 | |
PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
C2H3NO2 | |
Molar mass | 73.051 g·mol−1 |
Appearance | liquid |
Density | 1.073 g cm−3 |
Melting point | −55 °C (−67 °F; 218 K) |
Boiling point | 98.5 °C (209.3 °F; 371.6 K) |
78.9 g L−1 | |
Solubility in ethanol, acetone, and benzene | very soluble |
log P | -1.702 |
Vapor pressure | 45.8 mmHg |
Hazards | |
Flash point | 23.2 °C (73.8 °F; 296.3 K) |
Safety data sheet (SDS) | External MSDS |
Thermochemistry | |
Heat capacity (C)
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73.7 J mol−1 K−1 |
Std molar
entropy (S⦵298) |
324 J mol−1 K−1 |
Std enthalpy of (ΔfH⦵298)formation |
56 kJ mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Nitroethylene (also known as nitroethene) is a liquid organic compound with the formula C2H3NO2. It is the simplest nitroalkene, which are unsaturated carbon chains with at least one double bond and a NO2 functional group. Nitroethylene serves as a useful intermediate in the production of various other chemicals.
Properties
Nitroethylene has a
Production
Nitroethene can be produced by reacting
Reactions
Nitroethylene is a very electron deficient molecule. As a result, nitroethylene usually acts as the electrophile in reactions. Nitroethylene is capable of reacting spontaneously at temperatures as low as -100 °C, often as endothermic reactions. Common reactions for this molecule are cycloadditions, radical additions, and nucleophilic additions.[4]
Cycloaddition
Nitroethylene can act at the 2π electron source in a [4+2] cycloaddition. The nitro group in the molecule serves as an electron withdrawing group that makes the molecule a good candidate as a dienophile. It readily forms an adduct with cyclopentadiene, spiroheptadiene, and their derivatives in a [4+2] cycloaddition.[1]
Nitroethene can react at the 2π electron source in a [3+2] cycloaddition with nitrones.[5][6]
Nitroethylene is also reactive in domino-cycloaddition processes. For example, they can initially react with a chiral vinyl ether, and then react in a [3+2] cycloaddition with an electron deficient alkene such as dimethyl fumarate. The reactions are almost spontaneous at -78 °C.[7]
Radical polymerization
At very low temperatures (i.e. -78 °C), nitroethylene can polymerize with itself through initiation by one of its lone pairs. This process can be moderated by using t-butyl solvent. Research has been conducted on performing batch polymerization at room temperature in THF solvent. This process requires gamma ray irradiation for initiation. Termination of the polymerization requires a radical retardant, such as hydrogen bromide or hydrogen chloride. Water must be carefully removed prior to the polymerization, as nitroethylene is sensitive to polymerization by traces of water.[2]
Addition and Reduction
In addition to standard nucleophilic addition reactions on the C=C bond, nitroethylene can serve as a Michael acceptor in a Michael addition reaction. A typical Michael donor (i.e. ketone or aldehyde) can be used.[8] Like most nitro compounds, a platinum/palladium catalyzed reaction with hydrogen gas can reduce the nitro group to an amine group.
Another example is the Michael reaction of indole and nitroethylene.[1]
Uses
The main use of nitroethylene is as an intermediate reagent in chemical synthesis. One example is the production of N-(2-nitroethyl)-aniline with aniline at room temperature. The reaction utilizes benzene as a solvent and proceeds to about 90% yield in 12 hours.[9]
Another example of nitroethylene is from the coupling reaction with a vinyl Grignard reagent and a silyl glyoxalate to form a nitrocylopentanol. This process via a Henry reaction and is highly diastereoselective.[10]
References
- ^ a b c Ranganathan, D.; Rao, C. B.; Ranganathan, S.; Mehrotra, A.K; Iyengar, R. Nitroethylene: A Stable, Clean, and Reactive Agent for Organic Synthesis. J. Org. Chem. 1980, 45, 1185-1189.
- ^ a b Yamaoka, H.; Williams, F.; Hayashi, K. Radiation-Induced Polymerization of Nitroethylene. Trans. Faraday Soc., 1967, 63, 376-381. DOI: 10.1039/TF9676300376
- PMID 12492323.
- ^ Singleton, Daniel A. Nitroethylene. Publication. College Station: n.p., 2008. Wiley Online Library. Web. 18 Oct. 2012.
- ISSN 0009-3122.
- ISSN 1212-6950.
- ^ Denmark, S. E., Hurd A. R. Tandem [4+2]/[3+2] Cycloadditions with Nitroethylene. J. Org. Chem., 1998, 63(9), 3045-3050.
- ^ Y. Chi, L. Guo, N. A. Kopf, S. H. Gellman. Enantioselective Organocatalytic Michael Addition of Aldehydes to Nitroethylene: Efficient Access to γ2-Amino Acids. J. Am. Chem. Soc., 2008, 130, 5048-5049.
- ^ Nitroethylene properties. http://es.sw3c.com/chemical/formulas/cas-3638-64-0.html (accessed 11/6/2012).
- ^ Boyce G. R., & Johnson, J. S. Three-Component Coupling Reactions of Silyl Glyoxylates, Vinyl Grignard Reagent, and Nitroalkenes: An Efficient, Highly Diastereoselective Approach to Nitrocyclopentanols. Angewandte Chemie International Edition, 2010, 49(47), pp. 8930–8933