Methylenecyclopropane

Methylenecyclopropane
Names
Preferred IUPAC name
Methylidenecyclopropane
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.025.584 Edit this at Wikidata
UNII
  • InChI=1S/C4H6/c1-4-2-3-4/h1-3H2
    Key: XSGHLZBESSREDT-UHFFFAOYSA-N
  • InChI=1/C4H6/c1-4-2-3-4/h1-3H2
    Key: XSGHLZBESSREDT-UHFFFAOYAB
  • C=C1CC1
Properties
C4H6
Molar mass 54.09
Density 0.8 g/cm3
Boiling point 9 to 12 °C (48 to 54 °F; 282 to 285 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Methylenecyclopropane is an organic compound with the formula (CH2)2C=CH2. It is a hydrocarbon which, as the name suggests, is derived from the addition of a methylene (=CH2) substituent to a cyclopropane ring. It is a colourless, easily condensed gas that is used as a reagent in organic synthesis.

Synthesis

Methylenecyclopropane can be synthesized via an intramolecular cyclisation reaction from methallyl chloride by treatment with a strong base such sodium amide—sodium tert-butoxide (yield 43%)[1] or sodium bis(trimethylsilyl)amide with further treatment by sodium tert-butoxide (yield 72%).[2] Sodium tert-butoxide is used to isomerize byproduct 1-methylcyclopropene into methylenecyclopropane.

Reactions

Being a strained and unsaturated molecule methylenecyclopropane undergoes many reactions, especially in the presence of metal catalysts.[3] For example, methylenecyclopropanes can be converted to cyclobutenes in the presence of a platinum catalyst.[4] This can be considered similar to the ring expansion seen in vinylcyclopropane rearrangements

Methylene cyclopropane isomerization

Substituted methylenecyclopropanes can also be involved in trimethylenemethane cycloaddition reactions.

See also

References

  1. ^ Salaun, J. R.; Champion, J.; Conia, J. M. (1977). "Cyclobutanone from Methylenecyclopropane via Oxaspiropentane". Organic Syntheses. 57: 36. doi:10.15227/orgsyn.057.0036.
  2. ^ Binger, Paul; Brinkmann, Axel; Wedemann, Petra (2002). "Highly Efficient Synthesis of Methylenecyclopropane". Synthesis (10): 1344–1346. doi:10.1055/s-2002-33122. ISSN 0039-7881.
  3. ^ Nakamura, I.; Yamamoto, Y. (2002). "Transition Metal-Catalyzed Reactions of Methylenecyclopropanes". Advanced Synthesis and Catalysis. 344 (2): 111–129. doi:10.1002/1615-4169(200202)344:2<111::AID-ADSC111>3.0.CO;2-0.
  4. ^ PtCl2-Catalyzed Rearrangement of Methylenecyclopropanes Alois Fürstner and Christophe Aïssa J. Am. Chem. Soc.; 2006; 128(19) pp 6306 -6307; Abstract