聚合物负载季鏻盐催化 CO2 与环氧化物的环加成反应

 制备了聚合物负载的季鏻盐催化剂, 并用于 CO₂ 与环氧氯丙烷环加成反应中. 采用红外光谱、热分析、原子吸收光谱和扫描电子显微镜等手段测定了催化剂的结构、热性能、磷元素含量和表面形貌等. 考察了 CO₂ 压力、温度、催化剂用量和反应时间等对环加成反应性能的影响. 结果表明, 在催化剂用量为 0.09 g, CO₂ 压力为 4.5 MPa, 于 150 ^oC 反应 6 h 时, 3-氯甲基环碳酸酯收率可达 97.7%, 选择性大于 99%. 且催化剂易分离回收, 重复使用 5 次后产物收率和选择性没有明显下降. 同时探讨了该催化剂上 CO₂ 环加成合成环碳酸酯的可能机理.     

Immobilization of Ionic Liquid on a Covalent Organic Framework for Effectively Catalyzing Cycloaddition of CO2 to Epoxides

Transforming CO₂ into value-added chemicals has been an important subject in recent years. The development of a novel heterogeneous catalyst for highly effective CO₂ conversion still remains a great challenge. As an emerging class of porous organic polymers, covalent organic frameworks (COFs) have exhibited superior potential as catalysts for various chemical reactions, due to their unique structure and properties. In this study, a layered two-dimensional (2D) COF, IM4F-Py-COF, was prepared through a three-component condensation reaction. Benzimidazole moiety, as an ionic liquid precursor, was integrated onto the skeleton of the COF using a benzimidazole-containing building unit. Ionization of the benzimidazole framework was then achieved through quaternization with 1-bromobutane to produce an ionic liquid-immobilized COF, i.e., BMIM4F-Py-COF. The resulting ionic COF shows excellent catalytic activity in promoting the chemical fixation of CO₂ via reaction with epoxides under solvent-free and co-catalyst-free conditions. High porosity, the one-dimensional (1D) open-channel structure of the COF and the high catalytic activity of ionic liquid may contribute to the excellent catalytic performance. Moreover, the COF catalyst could be reused at least five times without significant loss of its catalytic activity.     

2D covalent organic framework: a photoactive heterogeneous catalyst for chemical fixation of CO2 over propargyl amines in water under sunlight

We have demonstrated the efficient synthesis of Pd(II)-based 2D mesoporous covalent organic framework (COF) along with a small amount of Pd(0), which is characterized by different characterization tools. These studies suggest that this material with low bandgap energy (Eg) of 1.73 eV can exhibit great photocatalytic activity toward CO₂ fixation reaction. Therefore, we have applied the Pd(II)-loaded COF as a new and effective photocatalyst for the preparation of oxazolidinone through the chemical fixation of CO₂. The reaction takes place in green solvent (H₂O) in absence of any base and under the sunlight at atmospheric pressure of CO₂ without using any cocatalyst. The reaction does not happen in the dark. In this context, we showed that a turnover number (TON) of 3.392 × 10³ can be achieved using the catalytic cycle under sunlight. The light dependency of the reaction is also checked by a control experiment via light modulation between light on and off. Furthermore, the catalyst shows efficient reusability for multiple reaction cycles, and also the heterogeneity test of the material suggests minimal active metal leaching during the catalysis reaction cycles. These results for the photocatalytic synthesis of oxazolidinone by CO₂ incorporation over COF under sunlight open a new environment-friendly green pathway for the formation of oxazolidinones.     

CO2的化学固定及碳酸亚烃酯的合成研究

报道了氯铝酞菁(PcAlCl)与n-BuPh3PBr, n-Bu4NBr, MePh3PI和n-Bu4NI等卤代季铵盐或季盐二元催化剂对CO2与环氧丙烷制备碳酸亚烃酯的环加成反应有明显的协同催化作用, 并初步探讨了其反应机理. 在100 ℃下, PcAlCl/n-BuPh3PBr的催化活性达360 mol/(mol*h), 选择性达99%; 而在同样条件下PcAlCl和n-BuPh3PBr单独对该反应的催化活性只有57 mol/(mol*h)和90 mol/(mol*h). 实验结果表明, PcAlCl与n-BuPh3PBr之间可能形成了1∶1型配合物, 导致催化活性显著增强.     

双中心多孔聚合物作为多相催化剂实现CO2在温和条件下高效转化

由于对化石燃料的高度依赖和二氧化碳(CO2)的过度排放,大气中CO2浓度从280 ppm上升到400 ppm左右,导致全球变暖和其他气候问题.在这种情况下,如何有效降低空气中的CO2浓度成为近年来最迫切的研究领域之一.另一方面,作为一种无毒、廉价且丰富的C1资源,CO2也可以转化为各种高附加值的工业产品,如甲酸、一氧化...     

COF固载铜盐催化苯硼酸与咪唑的Chan-Lam偶联反应

制备了一种含有联吡啶位点的共价有机骨架(COF)材料TpBpy,并通过配体上的联吡啶位点固载铜盐实现了功能化,得到的Cu@TpBpy具有大量的不饱和铜配位位点和高表面积,可用作苯硼酸与咪唑的Chan-Lam偶联反应的多相催化剂.通过优化溶剂、铜源、碱及反应时间等反应条件,发现使用质子极性溶剂MeOH时的反应产率最高,而Cu(OAc)₂@Tp Bpy是效果最佳的催化剂,可溶性有机碱三乙胺(TEA)的促进效果最好.Cu(OAc)₂@TpBpy在碱TEA的促进下于70℃催化咪唑与苯硼酸反应4 h后,得到目标产物1-苯基咪唑的最大产率为66%.在最优反应条件下进行了底物拓展,结果表明,取代基的位阻效应对催化体系影响显著,其中对位取代基的4-氯苯硼酸的产率最高(62%).     

Quaternary ammonium salt-catalyzed carboxylative cyclization of propargylic amines with CO2

By employing quaternary ammonium salts as catalysts, the carboxylative cyclization of the propargylic amines with CO₂ proceeded to afford the corresponding 2-oxazolidinones. In particular, tetra-n-butylammonium fluoride was the most effective catalyst for the reaction, providing a 2-oxazolidinone derivative in a maximum chemical yield of 99%. From a screening of the structure of a catalyst, it was found that both a quaternary ammonium cation and a basicity of the counter anion were essential to catalyze the carboxylative cyclization of the propargylic amines with CO₂.     

Basic Catalytic Performance of Amino and Acylamide Functionalized Metal-organic Framework in the Synthesis of Chloropropene Carbonate from CO2 Under Atmospheric Pressure

In this work, a metal-organic framework with free standing basic groups(e. g., amino and acylamide groups) decorated in the pore wall was utilized to catalyze the CO₂ cycloaddition reaction and its basic properties were tested in Knoevenagel condensation reactions. The results reveal that the metal-organic framework(MOF) material has excellent catalytic activity and high repeatability for the synthesis of chloropropene carbonate from CO₂ and epichlorohydrin with no co-catalyst under mild reaction conditions, suggesting that it is a promising heteroge-neous catalyst for CO₂ cycloaddition reaction.     

Enantioselective Synthesis of Acyclic Orthogonally Functionalized Compounds Bearing a Quaternary Stereocenter Using Chiral Ammonium Salt Catalysis

We herein report an asymmetric protocol to access a series of orthogonally functionalized acyclic chiral target molecules containing a quaternary stereogenic center by carrying out the enantioselective α-alkylation of novel orthogonally functionalized dioxolane-containing cyanoacetates under chiral ammonium salt catalysis. By using just 1 mol % of Maruoka's spirocyclic ammonium salt catalysts enantioselectivities up to e.r.=97.5 : 2.5 could be achieved and further functional group manipulations of the products were carried out as well.     

Microstructure Manipulation of Covalent Organic Frameworks (COFs)-based Membrane for Efficient Separations

Covalent organic framework(COF) membranes have exhibited great potential to become the next-generation membranes for efficient separations due to the diverse structures, ordered framework pores, tunable functionality and excellent stability. This review presents the microstructure manipulation strategies for separation performance enhancement of COF membranes in recent years. Based on the three mechanisms of molecular sieving, surface diffusion, and facilitated transport, the structural modulation methods to enhance the selectivity of COF membranes are analyzed in detail. Next, strategies of realizing ultrashort mass transfer pathways and ultralow mass transfer resistance for the permeability enhancement are elaborated. Furthermore, the framework stability in COFs, interlayer stability between COF nanosheets and interfacial stability between COF layer and substrate are discussed. Finally, we discuss the existing challenges and perspectives on the future development of COF membranes, targeting at identifying the most promising strategies and directions for the engineering of COF membranes.     

季膦盐型双功能金属Salen配合物催化二氧化碳转化为高附加值化学品

随着全球“温室效应”和能源危机的加剧,近几年二氧化碳作为一种丰富、无毒、廉价的碳一原料广受关注.目前,在温和条件下实现二氧化碳的化学转化仍然是一个十分具有挑战性的课题,其关键的科学问题是二氧化碳分子的有效活化.本文发现,在不添加任何助催化剂的条件下,季膦盐型双功能金属Salen配合物不仅能够以有机胺、含氢硅烷和二氧化碳为原料,在温和条件下通过N-甲酰化反应实现系列甲酰胺类衍生物的高效合成,而且能够催化二氧化碳和环氧化合物的环加成反应,从而实现环状碳酸酯的宏量制备.催化实验及动力学研究结果表明,该双功能催化剂通过金属活性中心和卤素阴离子之间的分子内协同催化作用,既可利用高活性锌氢键调控含氢硅烷中的硅氢键,又能通过高活性铝氧键激活环氧化物的三元环,进而导致二氧化碳的方便插入及高效活化.譬如:当使用1.0 mol％锌催化剂时,仅加入1倍当量的苯硅烷,在25℃C和0.5 MPa的条件下,反应6h后N-甲酰苯胺收率高达99％;而当使用0.5 mol％铝催化剂时,在100℃C和2.0 MPa的条件下反应2h,环加成反应转化率接近100％,环状碳酸酯选择性可达99％.另外,上述两个反应都表现出优异的底物扩展性,具有良好的官能团相容性.在此基础上通过构建反应动力学模型,采用在线红外跟踪技术,阐明了协同活化机制在二氧化碳催化转化过程中的作用原理及共性/个性规律,丰富并发展了二氧化碳活化的基本理论.最后,单组分催化剂可通过溶剂调变的方式很容易实现回收及再利用,表现出“均相催化,两相分离”的特点.循环使用五次后催化活性和选择性未见明显下降.     

CO2 Fixation with Epoxides under Mild Conditions with a Cooperative Metal Corrole/Quaternary Ammonium Salt Catalyst System

The cooperative catalytic activity of several metal corrole complexes in combination with tetrabutyl‐ammonium bromide (TBAB) has been investigated for the reaction of epoxides with CO₂ leading to cyclic carbonates. It was found that the use of just 0.05 mol % of a manganese(III)corrole with 2 mol % TBAB exhibits excellent catalytic activity under an atmosphere of CO₂.     

多孔骨架固定分子催化剂催化CO2加氢制备甲酸研究进展

近年来, 大气中CO₂含量急剧增加, 导致了严重的温室效应. 将CO₂作为C1资源转化为燃料或精细化学品引起了越来越多的关注. 开发高效、 稳定、 可回收利用的催化剂成为CO₂资源化利用的关键. 在众多的CO₂加氢催化剂中, 功能性多孔骨架材料固定型分子催化剂展示出优异的性能, 成为研究的热点之一. 功能性骨架材料, 如多孔有机聚合物(POPs)、 共价有机骨架(COFs)和金属有机骨架(MOFs), 具有比表面积大、 热稳定性高和可调性等特点, 在设计合成催化剂方面发挥着重要作用. 本文介绍了POPs/COFs/MOFs多孔骨架材料固定分子催化剂的开发及在催化CO₂合成甲酸领域的最新进展.     

A Three-dimensional Covalent Organic Framework for CO2 Uptake and Dyes Adsorption

Environmental pollution is one of the most severe problems facing today, including water pollution and the greenhouse effect. Therefore, developing materials with high-efficiency dyes adsorption and CO₂ uptake is significant. Covalent organic frameworks(COFs), as a burgeoning class of crystalline porous polymers, present a promising application potential in areas related to pollution regulation due to their exciting surface properties. Herein, we report a 3D COF with a high specific surface area(BET about 2072 m²/g) by utilizing tetrahedral and rectangle building blocks connected through[4+4] imine condensation reactions to synthesize. The obtained COF not only can separate dyes from water effectively but also shows a remarkable CO₂ uptake capacity. This research thus provides a promising material to remove dyes and adsorb CO₂ in environmental remediation.     

基于TiO2的绿色多相催化剂催化CO2与环氧化合物偶联反应

金属离子掺杂纳米TiO2(M-TiO2,M=Zn2+,Cu2+,Co2+,Mn2+,Ni2+)在CO2与环氧化合物的偶联反应中表现出较高的催化活性.反应以四正丁基碘化铵(TBAI)为共催化剂,在无溶剂条件下进行.考察了反应温度、反应时间和CO2压力在Zn-TiO2/TBAI体系中对反应性能的影响.作为无毒的多相催化剂,Zn-TiO2可循环使用5次,其催化活性没有明显降低.     

季铵盐催化氧化法合成硝基苯甲酸

研究了季铵盐A－1催化KMnO4分别氧化邻、对硝基甲苯合成邻、对硝基苯甲酸的反应。考察了不同相转移催化剂的催化活性及催化剂用量、反应温度、反应时间、KMnO4用量和反应体系酸碱性对反应的影响。在优化反应条件下，即以季铵盐A－1为相转移催化剂，KMnO4与硝基甲苯摩尔比为2．5：1，反应温度为95℃，反应时间为3h，在中性条件下进行反应，邻位、对位产物收率分别可达95%和92%。实验表明，季铵盐A－1对于KMnO4氧化硝基甲苯合成硝基苯甲酸的反应是一种优良的相转移催化剂。     

Eutectic Molten Salt Synthesis of Highly Microporous Macrocyclic Porous Organic Polymers for CO2 Capture

The development of porous materials is of great interest for the capture of CO₂ from various emission sources, which is essential to mitigate its detrimental environmental impact. In this direction, porous organic polymers (POPs) have emerged as prime candidates owing to their structural tunability, physiochemical stability and high surface areas. In an effort to transfer an intrinsic property of a cyclotetrabenzoin-derived macrocycle – its high CO₂ affinity – into porous networks, herein we report the synthesis of three-dimensional (3D) macrocycle-based POPs through the polycondensation of an octaketone macrocycle with phenazine-2,3,7,8-tetraamine hydrochloride. This polycondensation was performed under ionothermal conditions, using a eutectic salt mixture in the temperature range of 200 to 300 °C. The resulting polymers, named 3D-mmPOPs, showed reaction temperature-dependent surface areas and gas uptake properties. 3D-mmPOP-250 synthesized at 250 °C exhibited a surface area of 752 m² g⁻¹ and high microporosity originating from the macrocyclic units, thus resulting in an excellent CO₂ binding enthalpy of 40.6 kJ mol⁻¹ and CO₂ uptake capacity of 3.51 mmol g⁻¹ at 273 K, 1.1 bar.     

季铵盐型表面活性剂的合成及物化性能测定

从脂肪酸和N-(2-羟乙基)乙二胺开始,经过咪唑啉中间体,合成了12种未见文献报道的新化合物,其中3种为具有不同类型特性基团的新型两性表面活性剂、3种为新型阳离子表面活性剂,并测定了它们的物化性能。     

共价有机框架材料的离子化改性及其催化合成环碳酸酯的性能研究（英文）

共价有机框架(COFs)材料是继金属-有机框架材料之后,在拓扑学基础上发展起来的又一类多孔材料.这类材料是由轻质元素(C, H, O, N, B, Si等)通过可逆共价键连接而成的结晶性有机多孔聚合物,具有比表面积大、骨架密度低、孔道结构规整、可人为设计以及表面易修饰改性等特点,自2005年首次报道以来就引起了人们的广泛关注.经过十多年的发展,COFs材料已经被广泛用于气体吸附/分离、光电、能量存储、非均相催化等研究领域.由于材料的多孔性以及相对稳定的特点,近年来COFs材料作为催化剂或催化剂载体用于多相催化反应已经成为该领域的一个研究热点.但是到目前为止,COFs材料的离子化改性用于异相催化相关研究还相对较少.本文选择二维骨架中含有羟基基团的H₂P-DHPhCOF作为载体,通过两步接枝反应成功地将咪唑型离子液体引入到COF材料的孔道中;采用红外光谱、核磁共振、粉末X射线衍射、热失重分析等方法详细地表征了COF材料在后修饰过程中的变化.研究发现, 1,4-二溴丁烷与N-甲基咪唑基团的引入占据了部分孔道,导致框架材料的孔径和孔容减小.同时,我们还将该改性后的离子型C...     

A novel channel-wall engineering strategy for two-dimensional cationic covalent organic frameworks: Microwave-assisted anion exchange and enhanced carbon dioxide capture

A novel channel-wall engineering strategy of the porous materials cationic covalent organic frameworks(COFs)is established based on rapid microwave-assisted anion exchange reaction and utilized to prepare a set of new COFs.Due to the interaction between the carbon dioxide(C02)and the acetate anion,the resulting SJTU-COF-AcO shows greatly enhanced carbon dioxide capacity up to 1.7 times of the pristine COF.The effect of the counteranions to CO2 capacity in the cationic COFs is investigated for the first time,which demonstrates that our channel-wall engineering strategy is a promising way to tailor the property of COFs for high CO2 capacity.