Pauson-Khand Reaction, examples, mechanisms, and applications in organic chemistry have been discussed here:
The ring formation reaction involves [2+2+1] cycloaddition between an alkyne, an alkene, and carbon monoxide to form α, β-cyclopentenone known as Pauson-Khand reaction. In other words, it is one step-synthesis α, β-unsaturated cyclopentenone from the [2+2+1] cycloaddition of alkyne, alkene, and carbon monoxide, via an intermediate of alkynedicobalt hexacarbonyl complex. Pauson-Khand reaction is also known as Pauson-Khand cyclization, Pauson-Khand cycloaddition, or Pauson-Khand annulation.
Several Pauson-Khand reactions are intended as intramolecular reactions in order to attain stereochemical control. In the case of intermolecular Pauson-Khand reaction, due to steric hindrance, an alkene is positioned next to the less bulky acetylenic substituent during coordination, and a subsequent C-C bond forms between an alkene carbon and the closer acetylenic carbon, leading to the formation of the larger group on alkyne being found at the α-position of the resulting cyclopentenone.
The Pauson-Khand reaction has also been performed under a variety of conditions, including the use of chiral ligands, aldehydes as a carbon monoxide source, solid-supported cobalt catalysts to improve purification, colloidal cobalt nanoparticles, and so on.
The pauson-Khand reaction can be represented as:
Pauson-Khand Reaction Mechanism
The mechanism of the Pauson-Khand reaction can be carried out in the following way:
Applications of Pauson-Khand reaction
The Pauson–Khand reaction is commonly used to prepare cyclopentenones and their derivatives. This reaction also aids in the overall synthesis of a number of topologically complicated natural products with a variety of structural characteristics.
Pauson-Khand Reaction Video
What is Pauson-Khand reaction?
Pauson-Khand reaction is [2+2+1] cycloaddition between an alkyne, an alkene, and carbon monoxide to form α, β-cyclopentenone.
Uses of Pauson-Khand reaction
Pauson-Khand reaction is used to prepare cyclopentenone.
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