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
cobalt‐catalyzed hydroacylation of 1,6‐enynes with exogenous aldehydes in a domino sequence to construct enantioenriched ketones. The products were obtained in good yields with excellent regio‐, diastereo‐, and enantioselectivity. Furthermore, the chiral products served as valuable precursors to access complex spirocyclic scaffolds with three contiguous stereocenters. The asymmetric hydroacylation process exhibited
Cobalt-Catalyzed Asymmetric Hydroboration/Cyclization of 1,6-Enynes with Pinacolborane
作者:Songjie Yu、Caizhi Wu、Shaozhong Ge
DOI:10.1021/jacs.7b01708
日期:2017.5.17
We report a cobalt-catalyzed asymmetric hydroboration/cyclization of 1,6-enynes with catalysts generated from Co(acac)2 and chiral bisphosphine ligands and activated in situ by reaction with pinacolborane (HBpin). A variety of oxygen-, nitrogen-, and carbon-tethered 1,6-enynes underwent this asymmetric transformation, yielding both alkyl- and vinyl-substituted boronate esters containing chiral tetrahydrofuran
Rh-Catalyzed Aqueous Pauson-Khand-Type Cycloaddition in Microwave-Irradiated Medium
作者:Fuk Kwong、Albert Chan、Hang Lee
DOI:10.1055/s-2008-1078413
日期:2008.6
Microwave-assisted Rh-catalyzed dual catalysis in aqueous medium is described. This tandem process transforms the enyne to cycloadduct by cascade decarbonylation of formate ester and subsequently carbonylation of enyne under microwave-irradiated conditions.