直接硝化法合成邻硝基对甲酚

考察了用对甲酚和硝酸在二氯甲烷中合成邻硝基对甲酚的工艺条件,对影响反应的因素,如分散度、反应时间、反应温度、硝酸浓度等进行了优选,产率达到了82.3%.     

邻甲酚液相原位加氢反应

以Ni/CMK-3为催化剂,采用BET比表面积、X射线衍射和氢气程序升温还原对催化剂进行了表征.考察了不同Ni负载量、反应温度、反应初始压力及反应时间条件下,甲醇水相重整制氢与邻甲酚原位加氢的耦合反应.结果表明,当Ni负载量为20%、反应温度为230℃、反应前冷压为0.1 MPa、水-甲醇-模型化合物摩尔比为50∶15∶1及反应9 h时,邻甲酚转化率最高为45.4%.分别对比了甲醇、甲酸、甘油和异丙醇作为供氢溶剂对原位加氢反应的影响,其中以甲酸为供氢溶剂时,邻甲酚的转化率最高达82.2%.对比了甲酚3种同分异构体原位加氢的效果,发现邻甲酚和间甲酚的反应效果相差不大,而对甲酚的转化率则远低于邻甲酚和间甲酚.对20%Ni/CMK-3在原位加氢实验中的使用寿命进行了考察.     

镧系元素杂多钼磷酸钾的合成与性质研究

本文首次报道了K_(17)[Ln(P_2Mo_(17)O_(61))_2]·xH_2O(Ln=La~(3+),Ce~(3+),pr~(3+),Nd~(3+),Sm~(3+),Eu~(3+),Gd~(3+),Tb~(3+),Yb~(3+))的合成方法,取测定结果表明,与(?)系离子配位的配体P_2Mo_(17)O♂♀~-为α_2-型,Ln的配位数为8,推测其结构类似于K_(16)[Ce(Ⅳ)(α_2-P_2W_(17)O_(61))_2]·xH_2O,还进行了UV光谱、CV、极谱、TG-DTA及磁化率等性质的研究。     

邻硝基苯丙酮酸乙酯烯醇钾的合成和乙醇钾的制备新方法研究

邻硝基苯丙酮酸乙酯烯醇钾的合成和乙醇钾的制备新方法研究张本才，李宝林，李安祥（陕西师范大学化学系，西安７１００６２）邻硝基苯丙酮酸乙酯烯醇钾用作合成邻硝基苯甲醛（一种难于合成的重要化工原料，主要用来生产硝苯吡啶等药物）的关键中间体早有报道￣［１，２］...     

FTIR法研究乙酸酚醛酯固化邻甲酚环氧树脂的反应动力学

用ＦＴＩＲ原位测量技术研究了乙酸酚醛酯与邻甲酚环氧树脂在２－甲基咪唑存在下进行恒温固化反应的动力学，测定了固化反应的动力学参数，研究结果表明，固化反应是按照一级固化反应动力学进行的，根据羰基峰在固化反应前后的变化对固化反尖机理进行了初步探讨。     

Ni基催化剂在邻甲酚原位加氢反应中的催化性能

采用等体积浸渍法制备了一系列负载型Ni基催化剂,利用XRD、H2-TPR、NH3-TPD 等技术表征了催化剂的理化特性,考察了载体（CMK-3、SiO2ZrO2、MgO、Al2O3）、助剂（Cu、Ce、Fe）对Ni基催化剂理化特性的影响,测试了230 oC、0.1 MPa冷压下催化剂对邻甲酚原位加氢反应的性能．结果表明,在负载型镍基催化剂作用下,甲醇水相重整制氢反应可以与邻甲酚的原位加氢反应相耦合;以CMK-3为载体的催化剂活性明显优于其他三种载体,邻甲酚的转化率为45.35%;助剂的添加对催化剂性能影响显著,Fe 的引入使原位加氢体系的转化率降至40.49%,助剂Ce、Cu的加入提高了Ni/CMK-3催化剂的原位加氢反应性能,转化率分别提高至64.6%、66.8%,Cu的添加改变了产物的分布,在产物中出现了新产物甲苯;同时探讨原位加氢反应路径及反应机理．     

4-磺酸钾基邻苯二甲腈的合成

以4-硝基邻苯二甲腈为起始原料,经还原、重氮化、酰氯化、水解加碱中和得到酞菁水溶性前驱体4-磺酸钾基邻苯二甲腈,总收率22%,其结构由1H NMR,IR,MS和元素分析表征。     

改性金属氧化物电极用于降解邻甲酚的性能研究

采用电沉积法制备了Ti/Ti O2-NTs/Pb O2、Ti/Ti O2-NTs/Ce-Pb O2、Ti/Ti O2-NTs/Fe-Pb O2三种电极,采用X射线衍射(XRD)、线性伏安扫描(LSV)、电极加速寿命等手段分别对所制备电极进行了表征,并以邻甲酚作为目标污染物评价了电极的电催化活性。研究结果表明,被Fe、Ce修饰后的两种Pb O2电极的析氧电位、稳定性、电催化活性均高于未修饰电极,且所制备的三种电极的活性催化层均为β型Pb O2,邻甲酚在三种电极上的电催化降解反应均遵守一级反应动力学规律。其中被Fe修饰的Pb O2电极是降解邻甲酚综合性能最佳的电极,该电极析氧电位为2.12 V,当电流密度为10 m A/cm2时对邻甲酚去除率为99.74%,COD去除率为60.31%,加速寿命是未修饰电极的2.6倍。     

取代邻羟基苯乙酮的简便绿色合成

以对甲(氯、溴)苯酚(1a-c)为起始原料经酰化得对甲(氯、溴)苯酚乙酯,再以BF3·2HAc为催化剂无溶剂条件下实现Fries重排,以77.3%-80.4%的收率分别得到了5-甲基(氯、溴)邻羟基苯乙酮(2a-c);应用环境友好的聚乙二醇-400为溶剂,N-氯(溴、碘)代丁二酰亚胺为卤代试剂对邻羟基苯乙酮进行卤代反应,以61.8%-92.4%的收率制备3,5-二氯(溴、碘)邻羟基苯乙酮(4a-c);以邻羟基苯乙酮为原料,硝酸铈铵(CAN)为绿色硝化试剂,分别以29.8%和63.9%的收率得到了3位和5位硝化产物1-(2-羟基-3-硝基苯基)乙酮、1-(2-羟基-5-硝基苯基)乙酮(5a-b)。以上制备过程具有反应条件温和、后处理简单、环境友好等优点,为制备取代邻羟基苯乙酮提供了简单且绿色的新方法。     

二正丁基锡邻甲基水杨酸酯配合物的合成、结构及量子化学研究

二正丁基氧化锡和邻甲基水杨酸按物质的量比1∶1反应,合成了二正丁基锡邻甲基水杨酸酯配合物{[n-Bu2Sn(O2CC6H3OHCH3)]2O}2。经X-射线衍射方法测定了其晶体结构,配合物属单斜晶系,空间群为P21/c,晶体学参数a=2.436 89(10)nm,b=1.909 58(8)nm,c=1.632 04(7)nm,β=107.467 0(10)°,V=7.244 4(5)nm3,Z=4,Dc=1.438 g.cm-3,μ(Mo Kα)=14.19 cm-1,F(000)=3 184,R1=0.034 7,wR2=0.084 7。晶体中每一个结构基元包含了2个结构相同而空间取向不同的以Sn2O2构成的平面四元环为中心环的双核结构分子,锡原子均为五配位的畸变三角双锥构型。对其结构进行量子化学从头计算,探讨了配合物的稳定性、分子轨道能量以及部分前沿分子轨道的组成特征。     

聚碳酸酯的绿色合成工艺研究进展

综述了采用环境友好方法合成聚碳酸酯的工艺,并与光气法进行了对比分析.新方法以二氧化碳为原料,通过系列反应可以依次制得碳酸乙烯酯(EC)、碳酸二甲酯(DMC)、碳酸二苯酯(DPC),最后得到高纯度、高性能的聚碳酸酯(PC).其中,在得到的碳酸酯系列产品中,EC的收率为98%,选择性为100%;DMC的收率和选择性均可达到99.5%;DPC在出料口流出液中的含量可达92.6%,选择性为98%.     

Green Catalytic Process for Cyclic Carbonate Synthesis from Carbon Dioxide under Mild Conditions

As a renewable and abundant C₁ resource possessing multiple attractive characteristics, such as low cost, nontoxicity, non‐flammability, and easy accessibility, CO₂ conversion into value‐added chemicals and fuels can contribute to green chemistry and sustainable development. Since CO₂ is a thermodynamically inert molecule, the activation of CO₂ is pivotal for its effective conversion. In this regard, the formation of a transition‐metal CO₂ complex through direct coordination is one of the most powerful ways to induce the inert CO₂ molecule to undergo chemical reactions. To date, numerous processes have been developed for efficient synthesis of cyclic carbonates from CO₂. On the basis of mechanistic understanding, we have developed efficient metal catalysts and green processes, including heterogeneous catalysis, and metal‐free systems, such as ionic liquids, for cyclic carbonate synthesis. The big challenge is to develop catalysts that promote the reaction under low pressure (preferably at 1 bar). In this context, bifunctional catalysis is capable of synergistic activation of both the substrate and CO₂ molecule, and thus, could render CO₂ conversion smoothly under mild conditions. Alternatively, converting CO₂ derivatives, that is, the captured CO₂ as an activated species, would more easily take place at low pressure in comparison with gaseous CO₂. The aim of this Personal Account is to summarize versatile catalytic processes for cyclic carbonate synthesis from CO₂, including epoxide/CO₂ coupling reaction, carboxylation of 1,2‐diol with CO₂, oxidative cyclization of olefins with CO₂, condensation of vicinal halohydrin with CO₂, carboxylative cyclization of propargyl alcohols with CO₂, and conversion of the CO₂ derivatives.

     

Homogeneous Light‐Driven Catalytic Direct Carboxylation with CO2

Carbon dioxide is a ubiquitous and inexpensive one‐carbon source for chemical synthesis, and the efficient incorporation of CO₂ into organic molecules is of widespread research interest both for economic and ecological reasons. The methodologies to employ carbon dioxide as a single‐carbon unit to construct molecules relevant for agrochemical and pharmaceutical research include many elegant approaches, including asymmetric transformations. Even though remarkable achievements have been made in the field of light‐driven catalysis, especially photoredox catalysis, homogeneous light‐driven catalytic carboxylation by employing CO₂ as the key reagent has only become a subject of increasing attention in recent years. Therefore, this concise review will discuss the latest advances in this research area.     

磷酸二氢钾催化Yonemitsu缩合反应合成5-[(3-吲哚基)-芳甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物

以醛、吲哚和麦氏酸为原料,水和乙醇混合液为溶剂,在室温搅拌条件下以磷酸二氢钾为催化剂通过Yonemitsu缩合反应,合成了一系列的5-[(3-吲哚基)-芳甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物,产率为48%~98%,并通过X射线单晶衍射仪测定了化合物4o的晶体结构。 该方法能够有效的促使反应活性较低的4-甲基苯甲醛和4-甲氧基苯甲醛参与反应,以83%和60%的收率获得相应的目标产物,并具有反应条件温和、催化剂廉价易得、后处理简单、产物易于纯化、产率较高等优点,可用于合成3-取代吲哚类化合物。     

制备二苄基磷酸酯的工艺改进

以苯甲醇和三氯化磷为原料,通过三步反应合成了二苄基磷酸酯,总收率67.4%,其结构经IR表征。以三乙胺为缚酸剂,四氯化碳为前两步反应共同的溶剂,省略了第一步反应结束后的溶剂分离操作。     

Advances in Palladium-Catalyzed Carboxylation Reactions

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).     

2-氯烟酸绿色合成工艺

以烟酸为原料,经双氧水氧化制得N-氧化烟酸（2）; 2经氯化、水解并精制得2-氯烟酸,总收率76.8%,纯度≥99.5%,其结构经¹H NMR和¹³C NMR确证。     

Carboxylation Reactions with Carbon Dioxide Using N‐Heterocyclic Carbene‐Copper Catalysts

The development of versatile catalyst systems and new transformations for the utilization of carbon dioxide (CO₂) is of great interest and significance. This Personal Account reviews our studies on the exploration of the reactions of CO₂ with various substrates by the use of N‐heterocyclic carbene (NHC)‐copper catalysts. The carboxylation of organoboron compounds gave access to a wide range of carboxylic acids with excellent functional group tolerance. The C?H bond carboxylation with CO₂ emerged as a straightforward protocol for the preparation of a series of aromatic carboxylic esters and butenoates from simple substrates. The hydrosilylation of CO₂ with hydrosilanes provided an efficient method for the synthesis of silyl formate on gram scale. The hydrogenative or alkylative carboxylation of alkynes, ynamides and allenamides yielded useful α,β‐unsaturated carboxylic acids and α,β‐dehydro amino acid esters. The boracarboxylation of alkynes or aldehydes afforded the novel lithium cyclic boralactone or boracarbonate products, respectively. The NHC‐copper catalysts generally featured excellent functional group compatibility, broad substrate scope, high efficiency, and high regio‐ and stereoselectivity. The unique electronic and steric properties of the NHC‐copper units also enabled the isolation and structural characterization of some key intermediates for better understanding of the catalytic reaction mechanisms.     

盾构渣土基碳复合陶粒的制备及除磷性能

以固体废弃物地铁盾构渣土、稻草秸秆和氧化镁为主要原料,通过烧结法制备了一种盾构渣土基碳复合陶粒。考察了陶粒吸附磷的主要影响因素及平衡吸附量,并采用模型对实验数据进行拟合分析。结果表明,当盾构渣土、稻草秸秆粉末和氧化镁质量比为7∶2∶1,在最佳烧结条件700℃烧结可得到除磷性能最佳的陶粒。当吸附pH=6.3时,陶粒具有较高的磷吸附性能。吸附在12 h内基本能达到吸附平衡,该过程适合准二级动力学方程。盾构渣土基碳复合陶粒对磷酸盐的吸附符合Temkin等温模型,随温度升高吸附量逐渐增大,40℃下最大吸附量为12.76 mg/g。热力学参数ΔH=5.64 k J/mol0,ΔS=8.00 J/(K·mol)0,ΔG=3.16 k J/mol0,呈吸热、非自发的热力学特征,陶粒吸附磷后可通过2.0 mol/L的氢氧化钠溶液重新解吸回收。