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.
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。
Upgrading CO<sub>2</sub>
by Incorporation into Urethanes through Silver-Catalyzed One-Pot Stepwise Amidation Reaction
作者:Qing-Wen Song、Ping Liu、Li-Hua Han、Kan Zhang、Liang-Nian He
DOI:10.1002/cjoc.201700572
日期:2018.2
One‐pot two‐step stepwise reaction of terminal propargylicalcohols, carbondioxide, and primary/secondary amines for the effective synthesis of various urethanes through robust silver‐catalysed C‐O/C‐N bond formation is reported. Catalytic activities were investigated by controlling catalyst loading, reaction pressure and time, and very high turnover number (turnover frequency) was obtained: 3350
报道了末端炔丙醇,二氧化碳和伯/仲胺的一锅两步逐步反应,可通过牢固的银催化的C-O / C-N键形成来有效合成各种聚氨酯。通过控制催化剂的负载量,反应压力和时间来研究催化活性,并获得非常高的周转数(周转频率):在0.1 MPa下使用0.01 mol%的银催化剂可得到3350(35 h -1),最高可达到13360(139 h)-1)和0.005 mol%的银催化剂在2.0 MPa的室温下。该策略经过巧妙的调节,并以优异的收率和选择性同时提供了空前的高周转率(TON)和周转率(TOF)值,同时提供了范围广泛的β-氧代丙基氨基甲酸酯和1,3-氧杂唑烷-2-酮基序。
Silver Metal–Organic Framework Derived N-Doped Carbon Nanofibers for CO<sub>2</sub> Conversion into β-Oxopropylcarbamates
Developing efficient heterogeneous catalysts for chemical fixation of CO2 to produce high-value-added chemicals under mild conditions is highly desired but still challenging. Herein, we first reported an approach to prepare a novel catalyst (Ag@NCNFs), featuring Ag nanoparticles (NPs) embedded within porous nitrogen-doped carbon nanofibers (NCNFs), via growing a Ag metal–organic framework on one-dimensional