Ionic-liquid tagged prolines as recyclable organocatalysts for enantioselective α-aminoxylations of carbonyl compounds
作者:Sadaf Sadiq Khan、Jabbar Shah、Jürgen Liebscher
DOI:10.1016/j.tet.2011.01.031
日期:2011.3
With the aim of improving catalytic performance and recyclability various ionic-liquid-tagged organocatalysts (ILTOCs) based on (S)-proline as organocatalysts and triazolium or guanidinium salts as ionicliquid tags were applied in the asymmetric α-aminoxylation of ketones and aldehydes with nitrosobenzene in IL as solvents. Amongst such ILTOC’s compounds were found which performed better (ee >99%
Copper-Catalyzed Decarboxylative Cycloaddition of Propiolic Acids, Azides, and Arylboronic Acids: Construction of Fully Substituted 1,2,3-Triazoles
作者:Xiang-Xiang Wang、Yangchun Xin、Yi Li、Wen-Jin Xia、Bin Zhou、Rui-Rong Ye、Ya-Min Li
DOI:10.1021/acs.joc.9b03285
日期:2020.3.6
A copper-catalyzed decarboxylative cycloaddition of propiolic acids, azides, and arylboronicacids is described. The present reaction provides an efficient and convenient method for the synthesis of various fully substituted 1,2,3-triazoles from readily available starting materials. A possible mechanism is proposed.
Synthesis of 1,2,3-Triazolium Ionic Liquid-Supported Chiral Imidazolidinones and Their Application in Asymmetric Alkylation Reaction
作者:Yunkyung Jeong、Yunjeong Park、Jae-Sang Ryu
DOI:10.3390/molecules24183349
日期:——
ionic liquid-supported chiral imidazolidinones were developed. The feasibility of the ionic liquid-supported imidazolidinones as chiral auxiliaries was demonstrated in sequential propionylation-alkylation-cleavage reactions, which provided the chiral product with good to excellent chemical yields (up to 90%) and high selectivities (up to 94% ee). The progress of the reactions could be monitored by TLC
Highly active copper-catalysts for azide-alkynecycloaddition
作者:Zsombor Gonda、Zoltán Novák
DOI:10.1039/b920790m
日期:——
Bis-triphenylphosphano complexes of copper(I)-carboxylates serve as efficient catalysts for azide-alkyne cycloaddition. The triazole formation takes place straightforwardly at ambient temperature providing a wide variety of products with good yields in the presence of 0.005–0.05% catalyst.
A novel stereospecific synthesis of (Z)- and (E)-β-triazole-acrylates by the combined use of a multicomponent reaction and photocatalyst-free photoisomerization is presented. The former can be regarded as a furfuryl cation induced formal [3 + 2]-cycloaddition/ring-opening/esterification domino sequence, which provides fast access to a variety of structurally diverse (Z)-β-triazole-acrylates. The products