Cobalt Carbonyl-Mediated Carbocyclizations of Enynes: Generation of Bicyclooctanones or Monocyclic Alkenes
作者:Marie E. Krafft、Llorente Vicente R. Boñaga、James A. Wright、Chitaru Hirosawa
DOI:10.1021/jo016118v
日期:2002.2.1
Depending on the thermolytic conditions, dicobalthexacarbonyl-complexed enynes underwent cyclizations to provide different carbocyclic frameworks. Bicyclopentanones were formed from enyne-Co2(CO)6 complexes, or from enynes that were treated with Co2(CO)8, or more effectively, with Co4(CO)12 in an alcoholic solvent under a H2 or N2 atmosphere. This transformation proceeded via a sequential cyclocarbonylation
Scope of the Intramolecular Titanocene-Catalyzed Pauson−Khand Type Reaction<sup>1</sup>
作者:Frederick A. Hicks、Natasha M. Kablaoui、Stephen L. Buchwald
DOI:10.1021/ja990682u
日期:1999.6.1
A Pauson−Khandtype conversion of enynes to bicycliccyclopentenones employing the commercially available precatalyst titanocene dicarbonyl is described. This methodology shows excellent functional group tolerance for a group 4 metallocene-catalyzed process. The scope and limitations of this cyclization with respect to 1,6-, 1,7- and 1,8-enynes with a variety of terminal alkyne substituents, chiral
Inhibition of Enone Reduction in Aqueous-Phase Pauson-Khand Reactions
作者:Marie Krafft、James Wright、Llorente Boñaga
DOI:10.1055/s-2004-836053
日期:——
NMO-promoted room temperature cyclizations of the cobalt carbonyl complexes of substrates bearing terminal and internal alkynes gave exclusively the Pauson-Khand (PK) reaction adducts in a water-Triton X®-100 medium.
Catalytic activity of dodecacarbonyltetracobalt in aqueous media: a “greening” of the Pauson–Khand reaction
作者:Llorente V. R. Boñaga、James A. Wright、Marie E. Krafft
DOI:10.1039/b403827d
日期:——
The unprecedented reactivity of Co(4)(CO)(12) with enynes under aqueous conditions, representing the development of a mild and simple aqueous-phase cobalt-catalyzed PK reaction protocol, is described herein.
Catalyst precursors for the catalytic Pauson-Khand reaction
作者:M.E. Krafft、C. Hirosawa、L.V.R. Bonaga
DOI:10.1016/s0040-4039(99)01959-0
日期:1999.12
Dicobalt hexacarbonyl complexes of enynes serve as Co2(CO)8 surrogates for the intramolecular Pauson-Khand cycloaddition. Enynes with polar functional groups allow for easy separation of the catalyst cyclopentenone by-product (acid or base wash, silica gel plug column) from the desired cyclopentenone.