A new iron-catalyzed synthesis of cyclic carbonates from the corresponding vicinal diols and urea is described. This straightforward transformation allows for the preparation of a variety of five-membered carbonates by employing an inexpensive and environmentally benign iron salt as the catalyst. The use of readily available feedstocks such as urea and polyols makes this a sustainable process. As ammonia
Poly(4-vinylimidazolium)s/Diazabicyclo[5.4.0]undec-7-ene/Zinc(II) Bromide-Catalyzed Cycloaddition of Carbon Dioxide to Epoxides
作者:Ue Ryung Seo、Young Keun Chung
DOI:10.1002/adsc.201400047
日期:2014.6.16
Poly(4‐vinylimidazolium)s, derived from the self‐immobilization of 4‐vinylimidazoliums, with diazabicyclo[5.4.0]undec‐7‐ene (DBU) and zinc bromide (ZnBr2) are used as a highly efficient catalyst for the chemical fixation of carbon dioxide. This catalytic system has been applied for the preparation of cyclic carbonates from terminal epoxides and carbon dioxide. Many functional groups, including chloro
Catalytic Formation of Cyclic Carbonates using Gallium Aminotrisphenolate Compounds and Comparison to their Aluminium Congeners: A Combined Experimental and Computational Study
作者:Lucía Álvarez‐Miguel、Jesús Damián Burgoa、Marta E. G. Mosquera、Alex Hamilton、Christopher J. Whiteoak
DOI:10.1002/cctc.202100910
日期:2021.10.7
of gallium aminotrisphenolate compounds as catalysts for the synthesis of cyclic carbonates from epoxides and CO2. The results show that they are highly active, and more so than the corresponding aluminium congeners. The catalyst system is applicable at low and elevated temperatures across a wide substrate scope including terminal, internal, multiple and fully deuterated epoxides. Applying low catalyst
这项工作报告了使用氨基三酚镓化合物作为由环氧化物和 CO 2合成环状碳酸酯的催化剂. 结果表明它们具有高活性,并且比相应的铝同系物活性更高。该催化剂体系适用于低温和高温下的广泛底物范围,包括末端环氧化物、内部环氧化物、多重环氧化物和完全氘化环氧化物。应用低催化剂负载量可以获得 344,000 的 TON,突出了它们的稳定性。DFT 研究证实,与铝同系物相比,镓催化剂具有较低的能量分布。使用 Gutmann-Beckett 方法测量镓和氨基三酚铝化合物的路易斯酸度提供了实验证据,证明镓化合物比其铝同系物更具路易斯酸性。最后,
Unexpected Macrocyclic Multinuclear Zinc and Nickel Complexes that Function as Multitasking Catalysts for CO
<sub>2</sub>
Fixations
作者:Kazuto Takaishi、Bikash Dev Nath、Yuya Yamada、Hiroyasu Kosugi、Tadashi Ema
DOI:10.1002/anie.201904224
日期:2019.7.15
macrocyclic multinuclear ZnII and NiII complexes with binaphthyl‐bipyridyl ligands (L) were synthesized. X‐ray analysis revealed that these complexes consisted of an outer ring (Zn3L3 or Ni3L3) and an inner core (Zn2 or Ni). In the ZnII complex, the inner Zn2 part rotated rapidly inside the outer ring in solution on an NMR timescale. These complexes exhibited dual catalyticactivities for CO2 fixations:
合成了具有双萘基联吡啶基配体(L)的独特的自组装大环多核Zn II和Ni II配合物。X射线分析表明,这些络合物由外环(Zn 3 L 3或Ni 3 L 3)和内核(Zn 2或Ni)组成。在Zn II络合物中,内部Zn 2部分在NMR时标上在溶液中的外环内部快速旋转。这些配合物对CO 2固定具有双重催化活性:由环氧化物和CO 2合成环状碳酸酯和温度转换的N-甲酰化/ N胺与CO 2和氢硅烷的甲基化。
Palladium nanoparticles embedded over mesoporous TiO<sub>2</sub> for chemical fixation of CO<sub>2</sub> under atmospheric pressure and solvent-free conditions
作者:Resmin Khatun、Piyali Bhanja、Paramita Mondal、Asim Bhaumik、Debasis Das、Sk. Manirul Islam
DOI:10.1039/c7nj02459b
日期:——
CO2 fixation reactions are very demanding both from the perspective of mitigation of greenhouse gases as well as the successful utilization of this abundant C1 source. An efficient and recyclable catalytic system based on palladium nanoparticles embedded on mesoporous TiO2 (Pd@MTiO2) has been developed and it is explored as a heterogeneous catalyst for the synthesis of cyclic carbonates from the respective