Pauson-Khand Reaction-百灵威

The cobalt catalyzed formation of cyclopentenones from alkenes, alkynes and carbon monoxide is known as the Pauson-Khand reaction. The precise mechanism has not yet been fully elucidated, but previous studies have demonstrated that the larger alkyne substituent ends up next to the carbonyl group in the product. The regioselectivity with respect to an acyclic alkene is less predictable in intermolecular reactions, but reactions with cyclic alkenes are highly stereoselective. Intramolecular reactions proceed with both excellent regio- and stereoselectivity.

Reagents: Catalytic Transition Metal Complex (Co₂(CO)₈, Fe(CO)₅, Ru₂(CO)₁₂, etc.), CO
Reactant: Terminal or Internal Alkyne, Mono-, Di- or Trisubstituted Alkene
Product: Substituted Cyclopentenone
Type of Reaction: [2+2+1] Cycloaddition

Mechanism

Original Paper

Magnus, P.; Principe, L. M. Origins of 1,2- and 1,3-Stereoselectivity in Dicobaltoctacarbonyl Alkene-Alkyne Cyclizations for the Synthesis of Substituted Bicyclo[3.3.0]Octenones. Tetrahedron Letters 1985, 26 (40), 4851–4854.

Top Citations

Recent Advances in the Pauson–Khand Reaction and Related [2+2+1] Cycloadditions. Tetrahedron 2000, 56, 3263–3283.

The Intermolecular Pauson–Khand Reaction. Angewandte Chemie International Edition 2005, 44 (20), 3022–3037.

The Pauson–Khand Reaction: The Catalytic Age Is Here! Angewandte Chemie International Edition 2003,42 (16), 1800–1810.

Related Reactions

Synthesis of Cyclopentenones

Related Compounds

CO (CAS 630-08-0)

C8Co2O8 (CAS 10210-68-1)