Rhodium-BisbenzodioxanPhos Complex-Catalyzed Homogeneous Enantioselective Pauson-Khand-Type Cyclization in Alcoholic Solvents
作者:Fuk Yee Kwong、Hang Wai Lee、Liqin Qiu、Wai Har Lam、Yue-Ming Li、Hoi Lun Kwong、Albert S. C. Chan
DOI:10.1002/adsc.200505105
日期:2005.11
s was found to be highly effective in the co-operative processeses of aldehyde decarbonylation and cascaded enantioselective Pauson–Khand-type reactions. Various 1,6-enynes were transformed to the corresponding bicyclic cyclopentenones in good yields and enantiomeric excesses (up to 96% ee). The attractive feature of this new Rh-catalyzed homogeneous dual catalysis system is that the reaction can be
作者:Fuk Yee Kwong、Yue Ming Li、Wai Har Lam、Liqin Qiu、Hang Wai Lee、Chi Hung Yeung、Kin Shing Chan、Albert S. C. Chan
DOI:10.1002/chem.200401237
日期:2005.6.20
operationally simple protocol allows both catalyst and reactants to be handled under air without precautions. Various enynes were transformed to the corresponding bicycliccyclopentenones in good yield and enantiomeric excess (up to 95 % ee). A study of the electronic effects of the enyne substrates revealed a correlation between the electronic properties of the substrates and the ee value obtained in
A highly chemo- and stereoselective cobalt-catalyzed hydroarylative cyclization of 1,6-enynes with aromaticketones and esters to synthesize functionalized pyrrolidines and dihydrofurans is described. A mechanism involving cobaltacycle triggered C–H activation of aromaticketones and esters was proposed.
Stable and Surface‐active Co Nanoparticles Formed from Cation (
<i>x</i>
) Promoted Au/
<i>x</i>
‐Co
<sub>3</sub>
O
<sub>4</sub>
(
<i>x</i>
=Cs) as Selective Catalyst for [2+2+1] Cyclization Reactions
作者:Charles O. Oseghale、Batsile M. Mogudi、Oluwatayo Racheal Onisuru、Christianah Aarinola Akinnawo、Dele Peter Fapojuwo、Reinout Meijboom
DOI:10.1002/cctc.202001841
日期:2021.3.5
stable cobalt nanoparticles generated from alkali ion‐promoted gold catalyst for catalyzed carbonylative [2+2+1] cyclization reaction, is described. The gold nanoparticle‘s (AuNPs) role was assumed to dissociate the CO and H2 into atomic species on the catalyst surface by spillover, which in‐situ reduces the robust mesoporous cobalt oxide to metallic cobalt (Co3+→Co2+→Co), as the active catalytic species
Rhodium-catalyzed Cycloisomerization of Allyl Propargyl Ethers: An Efficient Synthesis of 3,4-Disubstituted Furans
作者:Shuichi Oi、Hiroshi Kawai、Yoshio Inoue
DOI:10.3987/com-05-s(t)27
日期:——
Cycloisomerization of allyl propargyl ethers was found to be catalyzed by a cationic rhodium complex to give 3,4-disubstituted furans in one step. Addition of carboxylic acids to the reaction improved the yield of the products. Generation of a rhodium hydride species from a rhodium complex with the carboxylic acids followed by hydrorhodation of the substrate with the rhodium hydride species would be