Editorial - (2021) Volume 10, Issue 6
Rearrangement reactions Two types of organic chemical reactions are described by the phrase "rearrangement." Within a relatively short-lived intermediate, a rearrangement may entail the one-step migration of a H atom or a bigger molecular fragment.
A rearrangement, on the other hand, can be a multi-step reaction with one of the steps being the migration of a H atom or a larger molecular fragment.
The migratory group attaches to one of the immediate neighbours of the atom to which it was originally connected in numerous rearrangements. This sort of rearrangement is known as (1,2)– rearrangements or (1,2) – shifts. These rearrangements are sigmatropic processes, with the numbers 1 and 2 indicating which subclass they belong to.
Curtius rearrangement or Curtius reaction
The heating of an acyl azide, which loses nitrogen and subsequently rearranges to an isocyanate, is the Curtius reaction.
RCON3 → R-N=C=O + N2
The isocyanate further reacts to generate urethane, amine, or substituted urea if the reaction is carried out in an alcoholic or aqueous solution. Claisen rearrangement The first and slowest stage in the isomerization of allyl aryl ethers to ortho allylated phenols is the conventional claisen rearrangement. In the actual rearrangement phase, which is a [3,3]-sigmatropic rearrangement, a cyclohexadienone is produced. Three valence electron pairs shift at the same time.
Cyclohexadienone is a non-aromatic molecule that cannot be separated and tautomerizes to the aromatic and thus more stable phenol very immediately.
An oxime is transformed to an amide in the Beckmann rearrangement. Treatment of an aldehyde or ketone with hydroxylamine yields an oxime. Ketoximes' OH group can act as a leaving group. Lactams are formed when cyclic oximes undergo the Beckmann rearrangement.
When the initial ketone's structure is compared to that of the products, it is clear that the combination of oxime production and Beckmann rearrangement results in the insertion of an NH group between the carbonyl and alpha carbons.
The Hofmann rearrangement occurs when a primary amide is treated with bromine and hydroxide ion in water, resulting in an amine that lacks the carbonyl group of the beginning amide.
Pericyclic reactions are described as reactions in which electrons undergo a coordinated cyclic shift. A pericyclic reaction is defined by two main features in this definition. Photochemical rearrangements Interconversion of isomeric compounds is known to occur in a variety of photoreactions. The term "rearrangement" is more generic than "isomerization," but for the reactions involving photochemical rearrangement, the distinction is irrelevant.
Citation: Sandhya K (2021) Editorial on Rearrangement Reactions. Organic Chem Curr Res. 10: 229.
Received Date: Jun 11, 2021 / Accepted Date: Jun 18, 2021 / Published Date: Jun 25, 2021
Copyright: © 2021 Sandhya K. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Competing interests: The authors have declared that no competing interests exist.