The Overman rearrangement is a
chemical reaction
A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...
that can be described as a
Claisen rearrangement
The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl vinyl ether will initiate a ,3sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl, d ...
of
allylic
In organic chemistry, an allyl group is a substituent with the structural formula , where R is the rest of the molecule. It consists of a methylene bridge () attached to a vinyl group (). The name is derived from the scientific name for garlic, . ...
alcohols to give allylic trichloroacetamides through an
imidate
Carboximidates (or more general imidates) are organic compounds, which can be thought of as esters formed between a carboximidic acid (R-C(=NR')OH) and an alcohol, with the general formula R-C(=NR')OR".
They are also known as imino ethers, sin ...
intermediate. The Overman rearrangement was discovered in 1974 by
Larry Overman.
The
sigmatropic rearrangement">,3sigmatropic rearrangement is
diastereoselective
In stereochemistry, diastereomers (sometimes called diastereoisomers) are a type of stereoisomer. Diastereomers are defined as non-mirror image, non-identical stereoisomers. Hence, they occur when two or more stereoisomers of a compound have dif ...
and requires heating or the use of
Hg(II) or
Pd(II) salts as catalysts. The resulting allylamine structures can be transformed into many chemically and biologically important natural and un-natural amino acids (like (1-
adamantyl
Adamantane is an organic compound with a formula C10H16 or, more descriptively, (CH)4(CH2)6. Adamantane molecules can be described as the fusion of three cyclohexane rings. The molecule is both rigid and virtually stress-free. Adamantane is the m ...
)glycine).
The Overman rearrangement may also be used for
asymmetric synthesis
Enantioselective synthesis, also called asymmetric synthesis, is a form of chemical synthesis. It is defined by IUPAC as "a chemical reaction (or reaction sequence) in which one or more new elements of chirality are formed in a substrate molecul ...
.
[''Asymmetric Overman Rearrangement'' '']Organic Syntheses
''Organic Syntheses'' is a peer-reviewed scientific journal that was established in 1921. It publishes detailed and checked procedures for the synthesis of organic compounds. A unique feature of the review process is that all of the data and ex ...
'', Vol. 82, p.134 (2005).
Article
)
See also
*
Pinner reaction
The Pinner reaction refers to the acid catalysed reaction of a nitrile with an alcohol to form an imino ester salt (alkyl imidate salt); this is sometimes referred to as a Pinner salt.
The reaction is named after Adolf Pinner, who first described ...
References
Further reading
*
*
* {{cite journal , last1 = Nishikawa , first1 = T. , last2 = Asai , first2 = M. , last3 = Ohyabu , first3 = N. , last4 = Isobe , first4 = M. , year = 1998 , title = Improved Conditions for Facile Overman Rearrangement(1), journal =
J. Org. Chem.
''The Journal of Organic Chemistry'', colloquially known as ''JOC'', is a peer-reviewed scientific journal for original contributions of fundamental research in all branches of theory and practice in organic and bioorganic chemistry. It is publ ...
, volume = 63 , issue = 1, pages = 188–192 , pmid = 11674062 , doi = 10.1021/jo9713924
Rearrangement reactions
Name reactions
Carboximidates