107319-64-2Relevant articles and documents
Ruthenium- and Rhodium-Catalyzed Ring-Opening Coupling Reactions of Cyclopropenones with Alkenes or Alkynes
Kondo, Teruyuki,Taniguchi, Ryosuke,Kimura, Yu
supporting information, p. 717 - 722 (2018/03/08)
Ru 3 (CO) 12 -catalyzed divergent ring-opening coupling reactions of a cyclopropenone with methyl acrylate (an electron-deficient alkene) are developed. Under an argon atmosphere, a decarbonylative linear codimer is obtained, while cyclopentenones are obtained under carbon monoxide (20 atm) without decarbonylation. While ruthenium complexes show no catalytic activity for the ring-opening cocyclization of cyclopropenones with ethylene (20 atm) or bicyclo[2.2.1]hept-2-ene (2-norbornene), rhodium complexes, especially [RhCl(η 4 -1,5-cod)] 2, show high catalytic activity for the desired cocyclization reactions to give the corresponding cyclopentenones in high yields and selectivities. In addition, [RhCl(η 4 -1,5-cod)] 2 realizes the catalytic ring-opening cocyclization of cyclopropenones with internal alkynes to give the corresponding cyclopentadienones. In all these reactions, ruthena- or rhodacyclobutenones are considered to be key intermediates, generated by strain-driven oxidative addition of a cyclopropenone C-C bond to an active ruthenium or rhodium species.
Mechanism of hydride abstraction by cyclopentadienone-ligated carbonylmetal complexes (M = Ru, Fe)
Thorson, Megan K.,Klinkel, Kortney L.,Wang, Jianmei,Williams, Travis J.
scheme or table, p. 295 - 302 (2009/04/13)
Cyclopentadienone-ligated ruthenium complexes, such as Shvo's catalyst, are known to oxidize reversibly alcohols to the corresponding carbonyl compounds. The mechanism of this reaction has been the subject of some controversy, but it is generally believed to proceed through concerted transfer of proton and hydride, respectively, to the cyclopentadienone ligand and the ruthenium center. In this paper we further study the hydride transfer process as an example of a coordinatively directed hydride abstraction by adding quantitative understanding to some features of this mechanism that are not well understood. We find that an oxidant as weak as acetone can be used to re-oxidize the intermediate ruthenium hydride without catalyst re-oxidation becoming rate-limiting. Furthermore, C-H cleavage is a significantly electrophilic event, as demonstrated by a Hammett reaction parameter of ρ = -0.89. We then describe how the application of our mechanistic insights obtained from the study have enabled us to extend the ligand-directed hydride abstraction strategy to include a rare example of an iron(0) oxidation catalyst. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
Synthesis and Rearrangement of Alkylaryl- and Aryl-substituted Dihydrosemibullvalenes by Thermolysis of 7,8-Fused Cyclo-octa-1,3,5-triene Derivatives
Greenfield, Simon,Mackenzie, Kenneth
, p. 1651 - 1666 (2007/10/02)
The thermal cycloaddition of a cyclobuteno-dienophile (1) with cyclopentadienones has been systematically investigated; the stereoisomeric adducts give convenient access by decarbonylation to a variety of tetra-aryl, methyltriphenyl-, triphenyl-, tri-t-butyl-, and dimethyldiphenyl-cyclo-octa-1,3,5-triene derivatives as the products of electrocyclic ring-opening of the valence-tautomeric primary products of cheletropic bridge-extrusion, viz. bicyclooctadienes.These compounds provide useful models for investigation of equilibria between the electrocyclic valence tautomers, the scope and mechanism for thermal cross-cyclisations in, for example, unsymmetrically substituted cyclooctatrienes, and the thermal vinyl-cyclopropane (1,3-allylic shift) isomerisation and/or H-atom transfer disproportionation of the resulting arylated and alkylaryldihydrosemibullvalenes.The results best accord with diradical pathways for cyclo-octatriene-dihydrosemibullvalene conversions and subsequent rearrangements.Usefull 13C and 1H n.m.r. structure correlations and new examples of cyclopentadienones are also reported.
