- Pauson–Khand reaction
The Pauson–Khand reaction (or PKR or PK-type reaction) is a
chemical reaction described as a[ 2+2+1] cycloaddition between analkyne , analkene andcarbon monoxide to form a α,β-cyclopentenone .Ref|1Ref|2 The originalcatalyst for thisorganic reaction wasdicobalt octacarbonyl but this has since been replaced by other catalyst systems.With asymmetrical alkenes or alkynes
regioselectivity is always an issue, but less so withintramolecular reactions .Variations
Wilkinson's catalyst based on thetransition metal rhodium also effectively catalyses PK reactions but requiressilver triflate as a co-catalyst Ref|3.Molybdenum hexacarbonyl is a carbon monoxide donor in PK-type reactions betweenallene s andalkyne s withdimethyl sulfoxide in toluene Ref|4.Cyclobutadiene als lends itself to a[ 2+2+1] cycloaddition although this reactant is generated in situ from decomplexation of stablecyclobutadiene iron tricarbonyl with CAN. Ref|5.References
# P. L. Pauson and I. U. Khand. "
Ann. N.Y. Acad. Sci. " 1977, "295", 2.
# Blanco-Urgoiti, J.; Añorbe, L.; Pérez-Serrano, L.; Domínguez, G.; Pérez-Castells, J. "Chem. Soc. Rev. " 2004, "33", 32. (DOI|10.1039/b300976a)
# Nakcheol Jeong, Byung Ki Sung, Jin Sung Kim, Soon Bong Park,Sung Deok Seo, Jin Young Shin, Kyu Yeol In, and Yoon Kyung Choi "Pure Appl. Chem.", Vol. 74, No. 1, pp. 85–91, 2002. ( [http://www.iupac.org/publications/pac/2002/pdf/7401x0085.pdf Online article] )
# "A New Allenic Pauson-Khand Cycloaddition for the Preparation of a-Methylene Cyclopentenones" Joseph L. Kent, Honghe Wan and Kay M. Brummond ( [http://www.pitt.edu/~kbrummon/Pubspdfs/paper.pdf Online Article] )
# "Intramolecular[ 2+2+1] Cycloadditions with (Cyclobutadiene)tricarbonyliron" Benjamin A. Seigal, Mi Hyun An, Marc L. Snapper "Angewandte Chemie International Edition " Volume 44, Issue 31 , Pages 4929 - 4932 2005. (DOI|10.1002/anie.200501100)ee also
*
Nicholas reaction
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