Formate as a CO surrogate for cascade processes: Rh-catalyzed cooperative decarbonylation and asymmetric Pauson–Khand-type cyclization reactions
作者:Hang Wai Lee、Albert S. C. Chan、Fuk Yee Kwong
DOI:10.1039/b702718d
日期:——
A rhodium-(S)-xyl-BINAP complex-catalyzed tandem formate decarbonylation and [2 + 2 + 1] carbonylative cyclization is described; this cooperative process utilizes formate as a condensed CO source, and the newly developed cascade protocol can be extended to its enantioselective version, providing up to 94% ee of the cyclopentenone adducts.
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
Microwave‐Assisted Rhodium‐Complex‐Catalyzed Cascade Decarbonylation and Asymmetric Pauson–Khand‐Type Cyclizations
作者:Hang Wai Lee、Lai Na Lee、Albert S. C. Chan、Fuk Yee Kwong
DOI:10.1002/ejoc.200800272
日期:2008.7
Microwave-assisted Rh–diphosphane-complex-catalyzed dual catalysis is reported. This cooperative process provides [2+2+1] cycloadducts by sequential decarbonylation of aldehyde or formate and carbonylation of enynes within a short period of time. Various O-, N-, and C-tethered enynes were transformed into the corresponding products in good yields. The first enantioselective version of this microwave-accelerated
Iron-Catalyzed Hydroborylative Cyclization of 1,6-Enynes
作者:Natalia Cabrera-Lobera、Patricia Rodríguez-Salamanca、Juan C. Nieto-Carmona、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/chem.201704401
日期:2018.1.19
reaction takes place under mild conditions, with inexpensive catalytic system and full atomeconomy. Mechanistic studies suggest the intermediacy of FeII-hydride active catalyst capable to react with the alkyne group prior to alkene insertion, and computational studies suggest the occurrence of barrierless σ-bond metathesis involving HBpin and Fe−C bonds along the catalytic cycle.