Beta scission is an important reaction in the
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
of thermal
cracking
Cracking may refer to:
* Cracking, the formation of a fracture or partial fracture in a solid material studied as fracture mechanics
** Performing a sternotomy
* Fluid catalytic cracking, a catalytic process widely used in oil refineries for crac ...
of
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...
s and the formation of
free radicals
In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired electron, unpaired valence electron.
With some exceptions, these unpaired electrons make radicals highly chemical reaction, chemi ...
. Free radicals are formed upon splitting the
carbon-carbon bond. Free radicals are extremely reactive and short-lived. When a free radical in a polymer chain undergoes a beta scission, the free radical breaks two carbons away from the charged carbon producing an
olefin
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as α-olefins.
The International Union of Pu ...
(ethylene) and a primary free radical, which has two fewer carbon atoms.
In organic synthesis, beta scission can be used to direct multistep radical transformations. For example, beta-scission of a weak C-S bond was used to favor one of two equilibrating radicals in metal free conversion of phenols to aromatic esters and acids via C-O transposition.
[Baroudi, A.; Alicea, J.; Flack, P.; Kirincich,J.; Alabugin, I. V. Radical O→C Transposition: a Metal-Free Process forConversion of Phenols into Benzoates and Benzamides, J. Org. Chem. 2011, 76, 1521-37. http://pubs.acs.org/doi/abs/10.1021/jo102467j .(Highlighted in https://www.organic-chemistry.org/Highlights/2011/17October.shtm).]
References
{{Reflist
Reaction mechanisms