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合成并表征了一类含新型胺基膦配体的Grubbs二代型钌卡宾烯烃复分解催化剂[RuCl2(H2IMes)·(R1HNPR22)(=CHPh)], 采用核磁共振波谱和单晶X射线衍射确定了催化剂的结构. 在室温条件下, 以N,N-二烯丙基-对甲苯磺酰胺的关环复分解反应(RCM)为模型, 考察了不同胺基膦配体对钌卡宾催化反应速率的影响. 结果表明, G2?1表现出最佳的催化活性. 通过底物研究发现, G2?1催化剂(摩尔分数, 1%)对双端烯及多端烯的RCM反应具有较好的活性和官能团适应性, 产物收率均>95%; G2?1催化剂同样适用于同(异)端烯底物的交叉复分解反应(CM), 其催化苯乙烯与3-苯氧基丙烯的CM反应时产物收率高达92%. 相似文献
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共价有机骨架是一种结晶性多孔材料,在非均相催化方面有着巨大的应用潜力.本文利用缺电子结构萘二酰亚胺(NDI)的衍生物作为单体,合成了一种新型功能性共价有机框架材料COF-FL-2. COF-FL-2具有较大的孔径和良好的吸附性能,骨架上的NDI结构能通过π-阴离子作用与杂多酸形成稳定的功能性复合材料.通过将磷钨酸(PTA)负载在COF-FL-2上,进一步制备了一种新型杂化杂多酸基复合物PTA@COF-FL-2.PTA@COF-FL-2对以过氧化叔丁醇(t-BuOOH)为氧化剂的烯烃环氧化反应表现出高的催化活性,可以在温和的条件下将环辛烯和1-辛烯环氧化成相应的环氧化物. PTA@COF-FL-2具有出色的稳定性,在反应条件下可长期使用,使用时无PTA浸出现象.此外, PTA@COF-FL-2回收非常方便,可以多次循环使用. 相似文献
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烯烃复分解反应是形成碳碳双键的重要反应之一,其发展与结构明确的钌催化剂[L2X2Ru=CHR]中配体的创制密切相关.1999年,环二氨基卡宾配体的引入极大提高了催化剂的活性、稳定性以及官能团适用性.2005年,Bertrand等发展了一种比环二氨基卡宾具有更强给电子能力的配体──环(烷基)(氨基)卡宾(CAACs)配体,且卡宾中心α位为一季碳原子,这使得其空间环境与其他类型卡宾配体有很大差异.首先概述了CAACs配体的合成及性质,紧接着讨论了其在烯烃复分解催化反应中的研究进展,最后对该领域所存在的问题进行简要分析并对其发展作了展望. 相似文献
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瑞典皇家科学院将2005年诺贝尔化学奖授予法国石油研究院的Yves Chauvin博士,美国加州理工学院的RobertH.G rubbs博士和美国麻省理工学院的R ichard R.Schrock博士,以表彰他们对发展有机合成中的复分解反应所作出的突出贡献。本文对2005年诺贝尔化学奖获奖者及其获奖工作———复分解反应作简单介绍。 相似文献
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为了得到稳定性更好、活性更高的烯烃复分解催化剂,本文采用有机合成的方法,以钌卡宾烯烃复分解催化剂为主体,用锌卟啉进行修饰,得到锌卟啉修饰的Grubbs-Hoveyda型双核钌卡宾烯烃复分解反应催化剂,产物结构使用核磁共振方法进行表征。 用0.1%化学计量催化剂催化几种代表性底物闭环复分解(RCM)反应产率能达到95%,对于特定的交叉烯烃复分解反应(CM),延长反应时间也能得到93%的较高产率。 研究结果为Grubbs-Hoveyda催化剂的修饰提供了新方法和理论依据。 相似文献
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Dr. Peng Dong Tingna Shao Jinlian Li Xiaohui Zhang Prof. Yu Zhao Prof. Xinhong Zhao Prof. Guixian Li 《欧洲无机化学杂志》2023,26(33):e202300483
Cyclohexane epoxide, which contains highly active epoxy groups, plays a crucial role as an intermediate in the preparation of fine chemicals. However, controlling the epoxidation pathway of cyclohexene is challenging due to issues such as the allylic oxidation of cyclohexene and the ring opening of cyclohexane epoxide during the cyclohexene epoxidation process to form cyclohexane oxide. This review focuses on the structure-activity relationships and synthesis processes of various heterogeneous transition metal-based catalysts used in cyclohexene epoxidation reactions, including molybdenum(Mo)-based, tungsten(W)-based, vanadium(V)-based, titanium(Ti)-based, cobalt(Co)-based, and other catalysts. Initially, the mechanism of cyclohexene epoxidation by transition metal-based catalysts is examined from the perspective of catalytic active centers. Subsequently, the current research of cyclohexene epoxidation catalysts is summarized based on the perspective of catalyst support. Additionally, the differences between alkyl hydroperoxide, hydrogen peroxide (H2O2), and oxygen (O2) as oxidants are analyzed. Finally, the main factors influencing catalytic performance are summarized, and reasonable suggestions for catalyst design are proposed. This work provides scientific support for the advancement of the olefin epoxidation industry. 相似文献
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The Synthesis of Quinazolinones from Olefins,CO, and Amines over a Heterogeneous Ru‐clusters/Ceria Catalyst 下载免费PDF全文
Jinghua An Yehong Wang Zhixin Zhang Zhitong Zhao Jian Zhang Prof. Feng Wang 《Angewandte Chemie (International ed. in English)》2018,57(38):12308-12312
Quinazolinones, an important class of heterocyclic compounds, have been widely used in pharmaceuticals because of their biological activity. However, the efficient and economical synthesis of quinazolinones has remained a challenge. A novel synthetic approach has now been developed to produce quinazolinones from olefins, CO, and amines over heterogeneous Ru‐clusters/ceria catalyst in the absence of acids, bases, and oxidants. Furthermore, H2O is generated as the only by‐product. A series of quinazolinones with aromatic or non‐aromatic substituents can be obtained in yields of up to 99 %. The Ru‐clusters/ceria can be reused at least four times. The analysis of the E‐factor (environmental impact factor) for the synthesis of 2‐ethyl quinazolinone suggests that this system is more environmentally friendly than other processes reported previously. 相似文献
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硅氢加成反应是有机硅化学领域最为重要的反应之一。自该反应于1947年被发现以来,大量的文献对其进行了报道。本文综述了近十年来应用于硅氢加成反应的各类负载型催化剂的研究进展,介绍了活性炭、二氧化硅、分子筛等负载过渡金属催化剂,重点介绍了有机-无机杂化载体负载Pt、Rh、Au等多相催化剂的制备方法及其在硅氢加成反应中的应用,并分析了其催化作用机理;总结了功能高分子化合物负载过渡金属在硅氢加成反应中的研究,和新型含不同官能基团的离子液体络合金属催化剂的制备方法及其对不饱和烃与含氢硅烷的硅氢加成反应的催化性能,总结和讨论了催化反应机理的研究,并对多相硅氢加成催化剂的发展方向进行了分析和展望。 相似文献
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In the cross-metathesis reaction of tri(methyl, ethoxy)vinylsilanes with propene and/or 1-butene catalyzed by RuCl2(PPh3)3 activated in benzene at 115–130 °C, a series of l-alkenylsilanes of general formula CH3(CH2)mCH = CHSiMe3−n(OEt)n, where m=0, 1, and n=0–3 (1-silyl-1-alkenes), as well as of formula CH2=C(Me)SiMe3−n(OEt)n, where n=1, 2 (2-silyl-1-alkenes), were obtained. Additional products determined were allysilanes of general formula CH2=CHCH2SiMe3−n(OEt)n and CH3CH= CHCH2SiMe3−n(OEt)n, where n=1–3. © 1997 John Wiley & Sons, Ltd. 相似文献
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Dr. Debasis Banerjee Dr. Rajenahally V. Jagadeesh Dr. Kathrin Junge Dr. Marga‐Martina Pohl Dr. Jörg Radnik Prof. Dr. Angelika Brückner Prof. Dr. Matthias Beller 《Angewandte Chemie (International ed. in English)》2014,53(17):4359-4363
A general epoxidation of aromatic and aliphatic olefins has been developed under mild conditions using heterogeneous CoxOy–N/C (x=1,3; y=1,4) catalysts and tert‐butyl hydroperoxide as the terminal oxidant. Various stilbenes and aliphatic alkenes, including renewable olefins, and vitamin and cholesterol derivatives, were successfully transformed into the corresponding epoxides with high selectivity and often good yields. The cobalt oxide catalyst can be recycled up to five times without significant loss of activity or change in structure. Characterization of the catalyst by XRD, TEM, XPS, and EPR analysis revealed the formation of cobalt oxide nanoparticles with varying size (Co3O4 with some CoO) and very few large particles with a metallic Co core and an oxidic shell. During the pyrolysis process the nitrogen ligand forms graphene‐type layers, in which selected carbon atoms are substituted by nitrogen. 相似文献
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生物乙醇近年来得到蓬勃发展,由乙醇制备低碳烯烃得到广泛关注。本文综述了近年来在乙醇制低碳烯烃领域ZSM-5催化剂的研究进展,介绍了经过金属或磷改性后的催化剂能够改善催化剂的性能,表现为降低催化剂表面酸量,调节酸强度,抑制芳构化和氢转移反应的发生。与未改性分子筛催化剂相比,改性后的催化剂能够显著提高催化剂的活性和乙醇转化产物中低碳烯烃的选择性,同时延长了催化剂的使用寿命。讨论了影响反应的一些因素和该反应的可能机理;展望了催化剂在乙醇制低碳烯烃中的发展方向,指出由乙醇制低碳烯烃是传统石脑油裂解的一条可替代途径。 相似文献
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Dr. Yubing Liu Dr. Alla Dikhtiarenko Naizhang Xu Jiawei Sun Jie Tang Kaiqiang Wang Dr. Bolian Xu Dr. Qing Tong Prof. Hero Jan Heeres Dr. Songbo He Prof. Dr. Jorge Gascon Prof. Dr. Yining Fan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(53):12134-12139
The synthesis of phosphine-based functional covalent organic frameworks (COFs) has attracted great attention recently. Herein, we present two examples of triphenylphosphine-based COFs (termed P-COFs) with well-defined crystalline structures, high specific surface areas, and good thermal stability. Furthermore, rhodium catalysts with these P-COFs as support material show high turnover frequency for the hydroformylation of olefins, as well as excellent recycling performance. This work not only extends the phosphine-based COF family, but also demonstrates their application in immobilizing homogeneous metal-based (e.g., Rh-phosphine) catalysts for application in heterogeneous catalysis. 相似文献
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多相不对称催化氢化研究进展* 总被引:7,自引:0,他引:7
本文综述了多相不对称催化氢化反应的最新研究进展.特别是对最近几年来两个典型的多相不对称催化氢化体系即酒石酸盐修饰镍催化剂催化β-酮酸酯的不对称氢化反应体系和金鸡纳生物碱修饰铂催化剂催化α-酮酸酯的不对称氢化反应体系进行了详细的介绍和讨论,同时展望了多相不对称催化氢化反应研究的前景. 相似文献