Pure Appl. Chem., 2008, Vol. 80, No. 5, pp. 903-911
doi:10.1351/pac200880050903
Metal carbonyl complexes and chirality*
Susan E. Gibson, Karina A. C. Kaufmann, Jennifer A. Loch, and Ayako Miyazaki
Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
Abstract:
A study of the Pauson-Khand reaction (PKR) based on Co2(CO)8 and binap has revealed that a key precatalyst is (binap)Co2(CO)6, and that alkynes add to this species to generate isomers that interconvert under typical PKR conditions. A 31P NMR study of (binap)(N-(prop-2-enyl)-N-(prop-2-ynyl)-p-toluenesulfonamide)Co2(CO)4 revealed that heating this species gives rise to an unexpected cobalt hydride species (binap)Co(CO)2H together with (binap)Co2(CO)6. Observation of a PKR reaction by 31P NMR spectroscopy revealed that the hydride species is generated during the course of the reaction.
Keywords: asymmetric synthesis; binap; cobalt carbonyl; cyclopentenone; Pauson-Khand reaction.
*Paper based on a presentation at the 14th International Symposium on Organometallic Chemistry Directed Towards Organic Synthesis (OMCOS-14), 2-6 August 2007, Nara, Japan. Other presentations are published in this issue, pp. 807-1194.
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