The Kharasch addition is an
organic reaction and a metal-catalysed
free radical addition of CXCl
3 compounds (X = Cl, Br, H) to
alkene
In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond.
Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...
s. The reaction is used to append trichloromethyl or dichloromethyl groups to terminal alkenes. The method has attracted considerable interest, but it is of limited value because of narrow substrate scope and demanding conditions.
The basic reaction proceeds through the CXCl
2 free radical
A daughter category of ''Ageing'', this category deals only with the biological aspects of ageing.
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Metabo ...
. Examples of organohalides are
carbon tetrachloride and
chloroform. Radicals are often generated by abstraction of a halide radical my a metal ion. The addition is an
anti-Markovnikov addition
In organic chemistry, Markovnikov's rule or Markownikoff's rule describes the outcome of some addition reactions. The rule was formulated by Russian chemist Vladimir Markovnikov in 1870.
Explanation
The rule states that with the addition of a ...
. Early work linked the addition to olefin polymerization and is therefore considered a first step into what was to become
atom transfer radical polymerization.
An example of Kharasch addition is the synthesis of 1,1,3-trichloro-n-nonane from
1-octene and chloroform using an iron-based catalyst.
History
The reaction was discovered by
Morris S. Kharasch in the 1940s.
References
{{Reflist
Organic reactions
Free radical reactions
Name reactions