organocatalyst for the atom‐economic conversion of a plethora of alkyl‐ and aryl‐substituted epoxides and isocyanates into oxazolidinones is described. A mechanism was proposed wherein the nucleophilic ring‐opening operation, and oxo‐ and carbamate‐anions stabilization occur cooperatively towards isocyanate fixation.
Selective Synthesis of 5‐Substituted
<i>N</i>
‐Aryloxazolidinones by Cycloaddition Reaction of Epoxides with Arylcarbamates Catalyzed by the Ionic Liquid BmimOAc
作者:Elnazeer H. M. Elageed、Bihua Chen、Binshen Wang、Yongya Zhang、Shi Wu、Xiuli Liu、Guohua Gao
DOI:10.1002/ejoc.201600474
日期:2016.7
5-substituted N-aryloxazolidinones in excellent yields. In addition, chiral 5-substituted oxazolidinones were synthesized by this procedure in good-to-excellent yields with enantiomeric excesses in excess of 99.9 % starting from chiral terminalepoxides. A possible reaction mechanism is discussed in accord with the results obtained by 1H NMR spectroscopy and DFT calculations, which indicate the cooperative activation
Transformation of Carbon Dioxide into Oxazolidinones and Cyclic Carbonates Catalyzed by Rare-Earth-Metal Phenolates
作者:Bin Xu、Peng Wang、Min Lv、Dan Yuan、Yingming Yao
DOI:10.1002/cctc.201600534
日期:2016.8.8
Rare‐earth‐metal complexes stabilized by amine‐bridged tri(phenolato) ligands were developed, and their activities in catalyzing transformations of CO2 were studied. A series of terminal epoxides and challenging disubstituted epoxides were converted into the respective cyclic carbonates in the presence of CO2 in yields of 58 to 96 %. In addition, these rare‐earth‐metal complexes also showed good activities
A lipase-catalyzed, cascade kineticresolution protocol has been established for the synthesis of 3-phenyloxazolidin-2-one derivatives with up to excellent enantioselectivities (95% ee). Candida antarctica lipase B showed high catalytic activity and stereoselectivity in sequential O- and N-alkoxycarbonylation processes.
Bifunctional organocatalysts for the conversion of CO<sub>2</sub>, epoxides and aryl amines to 3-aryl-2-oxazolidinones
作者:Ya-Fei Xie、Cheng Guo、Lei Shi、Bang-Hua Peng、Ning Liu
DOI:10.1039/c9ob00224c
日期:——
3-aryl-2-oxazolidinones is developed, which is achieved through a three component reaction between CO2, aryl amines, and epoxides with a binary organocatalytic system composed of organocatalysts and DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). The method allows wide scopes of epoxide and aryl amine substrates with various functional groups under mild reaction conditions. The control experiments indicate