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可见光催化作为一种新兴且强大的有机合成手段,具有洁净节能、优秀的官能团兼容性和良好的化学选择性等特征。氧气作为一种廉价、无污染的氧化剂,与可见光催化相结合,极大地促进了绿色化学的发展。本文主要对我们课题组近年来在可见光需氧氧化领域取得的成果做了简明的综述,并对其发展进行了展望。 相似文献
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采用均匀沉积-沉淀法制备了氧化铜修饰羟基磷灰石负载金催化剂(Au/CuO-HAP),并用原子吸收光谱、N2吸附脱附、X射线粉末衍射、透射电镜和X射线光电子能谱等方法对催化剂结构和形貌进行了表征.考察了催化剂对醇类液相需氧氧化的催化性能.与单金属Au/HAP或CuO-HAP相比较,双金属Au/CuO-HAP对苯甲醇氧化的催化活性和苯甲醛的选择性有显著提高,120 oC反应1.5 h,苯甲醇的转化率和苯甲醛的选择性分别达到99.7%和98.4%.在Au/CuO-HAP的催化下,其它类型的芳香醇均可高选择性转化为相应的醛或酮. Au/CuO-HAP催化剂有很好的稳定性和可回收性,4次回收后,其催化活性没有明显变化. 相似文献
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CuBTC(BTC:1,3,5-均苯三酸)作为一种高效、可重复利用的非均相催化剂,在催化领域有着重要的应用。论文主要研究了在Cu-TEMOP体系下,CuBTC对苯甲醇的需氧氧化反应的催化效果。研究表明,在CuBTC的催化下,多种苯甲醇衍生物被有效的氧化成相应的醛,并且该催化体系有着较高的选择性,能高效氧化伯醇。与传统的均相铜盐催化剂相比,Cu(II)能稳定的固定在CuBTC的刚性结构骨架中,并且催化活性不会降低。但是,羧酸类物质会使CuBTC催化剂中毒,所以CuBTC不适用于原料、产物或者副产物中存在羧酸的反应体系。 相似文献
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设计合成了一个含有苯并噻二唑结构单元的对三联苯二羧酸配体H21,将其与二甲基修饰的对三联苯二羧酸配体H22以物质的量比1:1在N,N-二甲基甲酰胺溶剂中混合后;在醋酸存在条件下,与ZrCl4发生溶剂热反应而得到金属有机骨架UiO-68-S.X射线粉末衍射表明该金属有机骨架具有UiO-68类型的框架结构;77 K温度下,氮气吸附等温曲线表明其具有较高的孔隙和比表面.在空气气氛和蓝光LED的照射下,金属有机骨架UiO-68-S可作为硫醚选择性氧化以及芳香硼酸羟基化的非均相光催化剂. 相似文献
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光学活性仲醇是非常重要的合成多种具有药物和生物活性化合物的原料和关键中间体,它们可通过外消旋仲醇的氧化动力学拆分获得。本文按氧化剂和手性催化剂的类别分类综述了近年来通过氧化动力学拆分获得光学活性仲醇方法的进展,并对一些方法的机理进行了描述。对以(-)-金雀花碱-钯(Ⅱ)、金雀花碱类似物-钯(Ⅱ)、N-杂环卡宾(NHC)-钯(Ⅱ)、手性双官能团-铱配合物以及手性(ON)-钌(salen)配合物催化的分子氧为氧化剂的仲醇的氧化动力学拆分进行了充分讨论。此外,还讨论了手性salen-锰(Ⅲ)催化二乙酰基碘苯以及通过不对称氢转移的方法对仲醇的氧化动力拆分。可以发现,(-)-金雀花碱-钯(Ⅱ)-分子氧体系在目前所有仲醇氧化动力学拆分体系中表现最佳。用于仲醇氧化动力学拆分的高效体系仍有待进一步开发。 相似文献
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Dr. Jie Liu Prof. Dr. Jan-E. Bäckvall 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15513-15518
The use of molecular oxygen in palladium-catalyzed oxidation reactions is highly widespread in organic chemistry. However, the direct reoxidation of palladium by O2 is often kinetically unfavored, thus leading the deactivation of the palladium catalyst during the catalytic cycle. In the present work, we report a highly selective palladium-catalyzed carbocyclization of bisallenes to seven-membered heterocycles under atmospheric pressure of O2. The use of a homogenous hybrid catalyst (Co(salophen)-HQ, HQ=hydroquinone) significantly promotes efficient electron transfer between the palladium catalyst and O2 through a low-energy pathway. This aerobic oxidative transformation shows broad substrate scope and functional group compatibility and allowed the preparation of O-containing seven-membered rings in good yields in most cases. 相似文献
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Shuyang Liu Miao Tian Dr. Xiubin Bu Dr. Hua Tian Prof. Xiaobo Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(28):7738-7744
Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle. 相似文献
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Lucia Veltri Roberta Amuso Raffaella Mancuso Bartolo Gabriele 《Molecules (Basel, Switzerland)》2022,27(1)
In this short review, we highlight the advancements in the field of palladium-catalyzed carbon dioxide utilization for the synthesis of high value added organic molecules. The review is structured on the basis of the kind of substrate undergoing the Pd-catalyzed carboxylation process. Accordingly, after the introductory section, the main sections of the review will illustrate Pd-catalyzed carboxylation of olefinic substrates, acetylenic substrates, and other substrates (aryl halides and triflates). 相似文献
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Practical Aerobic Oxidations of Alcohols and Amines with Homogeneous Copper/TEMPO and Related Catalyst Systems 下载免费PDF全文
Bradford L. Ryland Prof. Shannon S. Stahl 《Angewandte Chemie (International ed. in English)》2014,53(34):8824-8838
Oxidations of alcohols and amines are common reactions in the synthesis of organic molecules in the laboratory and industry. Aerobic oxidation methods have long been sought for these transformations, but few practical methods exist that offer advantages over traditional oxidation methods. Recently developed homogeneous Cu/TEMPO (TEMPO=2,2,6,6‐tetramethylpiperidinyl‐N‐oxyl) and related catalyst systems appear to fill this void. The reactions exhibit high levels of chemoselectivity and broad functional‐group tolerance, and they often operate efficiently at room temperature with ambient air as the oxidant. These advances, together with their historical context and recent applications, are highlighted in this Minireview. 相似文献
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Shuifa Qiu Yunyang Wei Prof. Dr. Guosheng Liu Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2751-2754
Taking the air! A PdII‐catalyzed intramolecular hydroamination of allenes coupled to alcohol oxidation has been developed. This reaction is performed by using a nitrogen‐based ligand under aerobic conditions, under which the molecular oxygen is used as the terminal oxidant for the reoxidation of Pd0 species to complete the catalytic cycle.
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Andrew J. Ingram Dr. Diego Solis‐Ibarra Prof. Richard N. Zare Prof. Robert M. Waymouth 《Angewandte Chemie (International ed. in English)》2014,53(22):5648-5652
The activation of O2 is a key step in selective catalytic aerobic oxidation reactions mediated by transition metals. The bridging trinuclear palladium species, [(LPdII)3(μ3‐O)2]2+ (L=2,9‐dimethylphenanthroline), was identified during the [LPd(OAc)]2(OTf)2‐catalyzed aerobic oxidation of 1,2‐propanediol. Independent synthesis, structural characterization, and catalytic studies of the trinuclear compound show that it is a product of oxygen activation by reduced palladium species and is a competent intermediate in the catalytic aerobic oxidation of alcohols. The formation and catalytic activity of the trinuclear Pd3O2 species illuminates a multinuclear pathway for aerobic oxidation reactions catalyzed by Pd complexes. 相似文献
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Joël Wellauer Dragan Miladinov Thomas Buchholz Dr. Jan Schütz Dr. René T. Stemmler Dr. Jonathan A. Medlock Dr. Werner Bonrath Prof. Dr. Christof Sparr 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(38):9748-9752
A mild photocatalytic phenol oxygenation enabled by a continuous-flow photoreactor using visible light and pressurized air is described herein. Products for wide-ranging applications, including the synthesis of vitamins, were obtained in high yields by precisely controlling principal process parameters. The reactor design permits low organophotocatalyst loadings to generate singlet oxygen. It is anticipated that the efficient aerobic phenol oxygenation to benzoquinones and p-quinols contributes to sustainable synthesis. 相似文献