Effective Guanidine-Catalyzed Synthesis of Carbonate and Carbamate Derivatives from Propargyl Alcohols in Supercritical Carbon Dioxide
作者:Nicola Della Ca'、Bartolo Gabriele、Giuseppe Ruffolo、Lucia Veltri、Tito Zanetta、Mirco Costa
DOI:10.1002/adsc.201000607
日期:2011.1.10
The reactions of propargyl alcohols with carbondioxide in supercriticalcarbondioxide or in acetonitrile with gaseous carbondioxide in the presence of organic bases as catalysts have been examined. Bicyclic guanidines are effective catalysts for the formation of α‐methylene cyclic carbonates under mild reaction conditions. Oxoalkyl carbonates, oxoalkyl carbamates or α‐methyleneoxazolidinones are
In this research, AgBr supported on an ionic gelation-based nanomaterial, was developed through the aqueous coprecipitation approach for the dendritic fibrous nanosilica (DFNS) production.
Bifunctional Silver(I) Complex-Catalyzed CO<sub>2</sub>Conversion at Ambient Conditions: Synthesis of α-Methylene Cyclic Carbonates and Derivatives
作者:Qing-Wen Song、Wei-Qiang Chen、Ran Ma、Ao Yu、Qiu-Yue Li、Yao Chang、Liang-Nian He
DOI:10.1002/cssc.201402921
日期:2015.3
The chemical conversion of CO2 at atmospheric pressure and room temperature remains a great challenge. The triphenylphosphine complex of silver(I) carbonate was proved to be a robust bifunctional catalyst for the carboxylative cyclization of propargylicalcohols and CO2 at ambient conditions leading to the formation of α‐methylene cyclic carbonates in excellent yields. The unprecedented performance
在大气压和室温下,CO 2的化学转化仍然是一个巨大的挑战。事实证明,碳酸银(I)的三苯基膦配合物是一种强大的双功能催化剂,可在环境条件下对炔丙醇和CO 2进行羧化环化反应,从而以极好的收率形成α-亚甲基环状碳酸酯。[(PPh 3)2 Ag] 2 CO 3的空前性能可能归因于CO 2和炔丙醇的同时活化。此外,催化物种的高度相容的碱性使炔丙醇与CO 2反应导致形成关键的烷基碳酸银中间体:较大的[(Ph 3 P)2 Ag I ] +有效激活碳-碳三键并增强烷基碳阴离子的O-亲核性,从而大大促进了分子内亲核环化。值得注意的是,该催化方案也适用于炔丙醇,仲胺和CO 2(在大气压下)反应以生成β-氧代丙基氨基甲酸酯。
Efficient chemical fixation of CO2 promoted by a bifunctional Ag2WO4/Ph3P system
作者:Qing-Wen Song、Bing Yu、Xue-Dong Li、Ran Ma、Zhen-Feng Diao、Rong-Guan Li、Wei Li、Liang-Nian He
DOI:10.1039/c3gc42406e
日期:——
anion is proposed. Recycling trials on carboxylative cyclization of propargyl alcohols and CO2 illustrate that the catalyst can be reused at least 4 times with retention of high catalytic activity and selectivity. Especially, it allows the direct and effective application in the one-pot synthesis of various oxazolidinones bearing exocyclic alkenes and carbamates in moderate to high yields upon the alternative
通过炔丙醇和CO 2的羧化组装,开发了一种高效的多相银催化的α-亚甲基环状碳酸酯基序的构建反应。在室温下,在无溶剂条件下,仅用1 mol%的Ag 2 WO 4和2 mol%的PPh 3以及大气中的CO 2平稳地进行这种CO 2固定方案,对环境无害且低能耗。简单的操作程序。值得注意的是,仅通过化学选择性就可以达到高达98%的分离的碳酸盐收率。另外,Ag 2 WO 4的双重活化能力面向炔丙基底物和CO 2的基础是,提出了银阳离子和钨酸根阴离子的协同催化机理。炔丙醇和CO 2的羧基环化的循环试验表明,该催化剂可重复使用至少4次,同时保留了高催化活性和选择性。特别地,它允许在交替引入伯胺或仲胺时以中等至高收率直接有效地将各种带有环外烯烃和氨基甲酸酯的恶唑烷酮单锅合成。
Co-immobilization of Laccase and TEMPO onto Glycidyloxypropyl Functionalized Fibrous Phosphosilicate Nanoparticles for Fixing CO2 into β-Oxopropylcarbamatesin
e-1oxyl radical into the nanospaces a fibre of phosphosilicate with laccase compound causes an unheard potent to be producing which called bifunctional nanocatalyst (TEMPO@FPS-laccase). TEMPO@FPS-laccase indicated proper catalytic activity for synthesis of β-oxopropylcarbamates in aqueous medium without any pollutants through a multi component coupling of CO2, amines and propargylalcohols in moderate
TEMPO 或将 2,2,6,6-四甲基哌啶-1氧基自由基锚定到纳米空间中,磷硅酸盐纤维与漆酶化合物会产生一种闻所未闻的强效物质,称为双功能纳米催化剂(TEMPO@FPS-漆酶)。TEMPO@FPS-漆酶在温和条件下通过CO2、胺和炔丙醇的多组分偶联,在没有任何污染物的水性介质中显示出适当的催化合成β-氧代丙基氨基甲酸酯的活性。游离漆酶可能无法回收,但可以在不同环境条件下轻松失效。酶固定化被称为增强对极端条件的抵抗力和稳定性以及漆酶回收的扩展方式。