Bifunctional One-Component Catalysts for the Addition of Carbon Dioxide to Epoxides
作者:Hendrik Büttner、Kornelia Lau、Anke Spannenberg、Thomas Werner
DOI:10.1002/cctc.201402816
日期:2015.2
Several bifunctional ammonium salts were synthesized and employed as one‐component catalysts for the conversion of CO2 and epoxides to produce cyclic carbonates. These catalysts show superior activities compared to their monofunctional analogs. A turnover number of up to 693 and a turnover frequency of up 392 h−1 could be achieved for the best catalyst. Moreover, the effect of various solvents has
合成了几种双功能铵盐,并将其用作单组分催化剂,用于将CO 2和环氧化物转化为环状碳酸酯。与它们的单官能类似物相比,这些催化剂显示出优异的活性。周转次数最多为693,周转频率最多为392 h -1可以达到最佳催化剂的效果。此外,已经研究了各种溶剂的作用。所有使用的溶剂和形成的产物对底物转化率都有负面影响。对于两种常规反应方案,分别在45和90°C下仔细研究了反应的范围和限制。在超过20个示例中,过滤后的分离产率为90%。此外,我们提出了环己烯基天然存在的环状碳酸酯的首次有机催化合成,其分子结构由XRD确定。此外,我们证明了该反应甚至可以在数克范围内进行,并且可以通过原位FTIR光谱进行监测。
Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide by Using Bifunctional One-Component Phosphorus-Based Organocatalysts
作者:Hendrik Büttner、Johannes Steinbauer、Thomas Werner
DOI:10.1002/cssc.201500612
日期:2015.8.24
Numerous bifunctionalorganocatalysts were synthesized and tested for the atom‐efficient addition of carbondioxide and epoxides to produce cyclic carbonates. These catalysts are based on phosphonium salts containing an alcohol moiety in the side chain for substrate activation through hydrogen bonding. In the model reaction, converting 1,2‐butylene oxide with CO2, 19 catalysts were tested to determine
Rh-ammonium iodide catalyst showed high performance for hydrosilylation-CO2 cycloaddition reaction sequences. The catalyst was prepared by surface grafting of Rh and the silane-coupling reaction of the ammonium iodide moiety. The acceleration of each catalytic reaction was realized due to the concerted catalysis between Rh species, immobilized organic functions, and surface Si-OH groups. As a result
Cooperative Multifunctional Organocatalysts for Ambient Conversion of Carbon Dioxide into Cyclic Carbonates
作者:Ning Liu、Ya-Fei Xie、Chuan Wang、Shi-Jun Li、Donghui Wei、Min Li、Bin Dai
DOI:10.1021/acscatal.8b01925
日期:2018.11.2
N-heterocyclic carbene precursor and a carboxyl group as proton transfer agent were synthesized and used as organocatalysts for the cycloaddition of epoxides with CO2. In this context, we have demonstrated the high activity of these one-component organocatalysts in the CO2 transformation to cyclic carbonates under ambient conditions (room temperature, 1 bar of CO2). The catalytic potential of these multifunctional
合成了一系列具有N杂环卡宾前体和羧基作为质子转移剂的钳型化合物,并将其用作有机催化剂,用于环氧化物与CO 2的环加成反应。在这种情况下,我们已经证明了这些单组分有机催化剂在环境条件(室温,1 bar CO 2)下从CO 2转化为环状碳酸酯的高活性。这些多功能有机催化剂在具有挑战性的内部环氧化物上的催化潜力特别值得一提,因为能够介导内部环氧化物与CO 2的环加成反应的有机催化剂在温和的条件下仍然稀缺。通过控制实验和DFT计算阐明了分子内的协同激活机制。