Hydrovinylation

In organic chemistry, hydrovinylation is the formal insertion of an alkene into the C-H bond of ethylene. The more general reaction, hydroalkenylation is the formal insertion of an alkene into the C-H bond of any terminal alkene. The reaction is catalyzed by metal complexes. A representative reaction is the conversion of styrene and ethylene to 3-phenybutene:[1]

PhCH=CH2 + CH2=CH2 → CH3-CH(Ph)-CH=CH2.

Ethylene dimerization to give 1-butene is a related reaction.

In the Dimersol and Alphabutol Processes, alkenes are dimerized for the production of gasoline and for comonomers such as 1-butene. These processes operate at several refineries across the world at the scales of about 400,000 tons/year (2006 report).[2]

Hydroarylation

Hydroarylation is again a special case of hydrovinylation. Hydroarylation has been demonstrated for alkyne and alkene substrates. An early example was provided by the Murai reaction, which involves the insertion of alkenes into a C-H bond of acetophenone. The keto group directs the regiochemistry, stabilizing an aryl intermediate.[3]

A Murai reaction (X = directing group, typically X = O).

When catalyzed by palladium carboxylates, a key step is electrophilic aromatic substitution to give a Pd(II) aryl intermediate.[4]

References

  1. ↑ T. V. RajanBabu, G. A. Cox (2014). "Hydrovinylation Reactions in Organic Synthesis". Comprehensive Organic Synthesis II (Second Edition). 5. pp. 1582–1620. doi:10.1016/B978-0-08-097742-3.00533-4.
  2. ↑ Yves Chauvin (2006). "Olefin Metathesis: The Early Days (Nobel Lecture)". Angew. Chem. Int. Ed. 45: 3740–3747. doi:10.1002/anie.200601234.
  3. ↑ Murai, Shinji; Kakiuchi, Fumitoshi; Sekine, Shinya; Tanaka, Yasuo; Kamatani, Asayuki; Sonoda, Motohiro; Chatani, Naoto (1993-12-09). "Efficient catalytic addition of aromatic carbon-hydrogen bonds to olefins". Nature. 366 (6455): 529–531. Bibcode:1993Natur.366..529M. doi:10.1038/366529a0.
  4. ↑ Jia, C.; Kitamura, T.; Fujiwara, Y. (2001). "Catalytic Functionalization of Arenes and Alkanes Via C-H Bond Activation". Acc. Chem. Res. 34: 633–639. doi:10.1021/ar000209h.
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