多孔碳包覆铜纳米颗粒的制备及性能表征——推荐一个化学综合实验

以Cu-MOF为前驱体,通过热解法制备氮掺杂多孔碳包覆铜纳米材料,采用X射线粉末衍射仪(XRD)、场发射扫描电子显微镜(SEM)和傅立叶变换红外光谱仪(IR)等仪器对产物的形貌和组成进行表征。考察了不同热解温度对多孔碳材料形貌和组成的影响,探究其在硝基苯还原反应中的催化性能,并优化了反应条件。将材料的制备、表征和性能探究设计成一个综合实验,能够培养学生的科研思维和综合分析能力。     

铁、锰、铜和水杨醛缩金刚烷胺席夫碱配体原位催化5-羟甲基糠醛氧化制备5-甲酰基呋喃-2-羧酸

本研究将铁、锰、铜和金刚烷胺缩水杨醛衍生的席夫碱配体组成的原位催化剂用于催化5-羟甲基糠醛(5-Hydroxymethylfurfural,简称HMF)选择性氧化制备5-甲酰基呋喃-2-羧酸(5-formyl-2-furancarboxylic acid,简称FFCA)。通过核磁共振（NMR）、红外（FT-IR）和单晶衍射对配体和配合物进行了表征,并对氧化反应时间、反应温度、MnCl2·4H2O与配体物质的量比、氧化剂和催化剂用量等反应条件进行优化,在最优化条件下,HMF转化率为100%,并且可以获得收率为52.1%的FFCA。根据反应结果对Mn金属配合物催化的HMF氧化反应过程进行了分析。     

4,4′-联苯二甲酸合成工艺研究

以医药中间体合成过程中产生的副产物4,4′-二甲基联苯为原料,经氯代反应生成4,4′-双(三氯甲基)联苯,然后水解制得4,4′-联苯二甲酸;对氯代反应的历程进行了探讨,并通过正交实验考察了反应参数对4,4′-联苯二甲酸收率的影响,得到了优化工艺条件,优化工艺条件下的验证实验表明:反应总收率达到93.40%,纯度达99.20%。采用IR、~1HNMR对产物的结构进行表征,通过HPLC对生成的4,4′-联苯二甲酸的纯度进行测定。该合成工艺具有环境友好、工艺操作简单、转化率及收率高、经济性好等优点,适合工业化大规模生产。     

铜-二正丁胺络合体系催化的2,6-二甲基苯酚聚合反应研究

采用间歇溶液聚合法制备了聚苯醚(PPO),对铜-二正丁胺络合体系催化的2,6-二甲基苯酚聚合反应进行了研究。探讨了络合反应对催化剂活性的影响,优化了二正丁胺用量以及单体的浓度和滴加速度。实验表明聚合反应适宜的条件是:温度为(32±2)℃,聚合反应时间为2.5-3.0h。     

2,5-二(2-羟乙氨基)-1,4-苯醌合成方法的改进

以对苯二酚和乙醇胺为原料,直接合成2,5-二(2-羟乙氨基)-1,4-苯醌,并对产物进行红外、紫外、质谱及核磁表征.采用正交设计法对实验条件进行优化,乙醇为溶剂,对苯二酚和乙醇胺物质的量比为1∶5,在50℃下,反应2h,最高产率达到72.8%.产物为针状晶体,纯度较高.     

5(6)-氨基-1-(4-氨基苯基)-1,3,3-三甲基茚满合成及工艺优化

以5(6)-硝基-1-(4-硝基苯基)-1,3,3-三甲基茚满为原料,Pd/C为催化剂,用氢气还原合成5(6)-氨基-1-(4-氨基苯基)-1,3,3-三甲基茚满。红外、核磁表征了产物结构;考察了反应温度、反应时间、充入氢气压力及催化剂用量四个因素,设计正交试验对还原工艺条件进行优化分析。结果表明,对粗产率的影响显著程度依次为充入H2压力、反应时间、反应温度和催化剂用量,获得了优化工艺条件,即反应温度70℃、反应时间为2 h、充入H2压力为1.5 MPa,催化剂用量为5(6)-硝基-1-(4-硝基苯基)-1,3,3-三甲基茚满的10%。     

N-羟基邻苯二甲酰亚胺/Co(acac)_2催化的α-紫罗兰酮的氧化反应

以分子氧(O_2)为氧化剂,在无溶剂条件下,研究了N-羟基邻苯二甲酰亚胺/乙酰丙酮亚钴(Ⅱ)体系对α-紫罗兰酮的催化氧化反应,分析了氧化产物,主要得到α-紫罗兰酮的烯丙位氧化产物5-氧代-α-紫罗兰酮,同时生成少量环氧α-紫罗兰酮及重排产物4-氧代-β-紫罗兰酮和环氧β-紫罗兰酮,提出了可能的反应机理,化合物的结构经IR、~1H NMR、MS和EA等测试技术得以表征;为了提高5-氧代-α-紫罗兰酮的选择性和催化氧化反应的转化率,优化了催化氧化反应的工艺条件:当反应温度为70 ℃,氧气压力为1.0 Mpa,N-羟基邻苯二甲酰亚胺和乙酰丙酮亚钴(Ⅱ)用量分别为α-紫罗兰酮的25%和1.0%,反应10 h,5-氧代-α-紫罗兰酮的产率达53.4%,反应转化率达95.0%以上,平行实验表明,实验重复性良好.     

本科生有机化学实验与前沿科学研究的融合—四(4-甲基苯基)乙烯的合成、表征及聚集发光性能研究

四苯乙烯(TPE)及其衍生物,作为一类典型的聚集诱导发光分子,由于其合成简单、易于修饰和发光性能优异等优点,已被广泛的应用于化学生物传感器、生化检测、生物成像和有机光电材料等领域。在此,我们将聚集诱导发光这一前沿研究热点融入有机化学实验教学中,进行教学对象为化学专业本科生的前沿有机化学实验设计：四(4-甲基苯基) 乙烯的合成、表征及聚集发光性能研究。该实验内容包括通过McMurry 偶联反应合成四(4-甲基苯基) 乙烯、四(4-甲基苯基) 乙烯的结构表征,以及利用紫外-可见分光光度计和荧光光谱仪对其聚集诱导发光性能进行研究。通过本实验,使学生了解聚集诱导发光这一科学研究前沿领域,激发学生对科学研究的兴趣、拓展科研视野、激发科研热情、培养学生的科研探究能力。本实验综合了有机化学、仪器分析和发光材料等知识点的学习,培养学生的实验操作技能,提升学生的综合及创新能力,建议纳入高年级中级有机化学实验课程。     

基于氨基酸的Cu(Ⅱ)-色氨酸MOF催化剂上环氧化物与CO2环加成反应

由天然的/生物单元(氨基酸)构成的金属有机框架材料(MOFs)具有自然属性和丰富的酸/碱位和官能团,因而可用于CO2化学中.本文报道了氨基酸系含铜MOF(CuTrp,Trp = L-色氨酸)的催化效率.以甲醇为溶剂,在室温采用直接混合法合成了CuTrp催化剂,该方法具有很高的能量效率.采用X射线衍射、红外光谱、热重分析、电感耦合等离子体发射光谱法、扫描电镜和BET分析等手段对该催化剂进行了表征.采用环氧化物与CO2环加成制备环状碳酸酯反应评价了CuTrp催化剂活性.结果表明,在无溶剂条件下,CuTrp 催化剂可与四丁基溴化铵助催化剂发生协同作用.通过条件实验确定了优化的反应条件,并基于该实验结果和前期的密度泛函理论计算结果提出了反应机理.另外,CuTrp 催化剂在水中也表现出令人满意的稳定性,可重复使用三次以上而活性无明显下降.     

氮羟基邻苯二甲酰亚胺催化的α-紫罗兰酮的氧化反应

以分子氧（O₂）为氧化剂,在无溶剂条件下,研究了N-羟基邻苯二甲酰亚胺/乙酰丙酮亚钴(Ⅱ)体系对α-紫罗兰酮的催化氧化反应,分析了氧化产物,主要得到α-紫罗兰酮的烯丙位氧化产物5-氧代-α-紫罗兰酮,同时生成少量环氧α-紫罗兰酮及重排产物4-氧代-β-紫罗兰酮和环氧β-紫罗兰酮,提出了可能的反应机理,化合物的结构经IR, ¹H NMR, MS和EA等手段得以表征;为了提高5-氧代-α-紫罗兰酮的选择性和催化氧化反应的转化率,优化了催化氧化反应的工艺条件：当反应温度为70 ℃,氧气压力为1.0 MPa,N-羟基邻苯二甲酰亚胺和乙酰丙酮亚钴(Ⅱ)用量分别为α-紫罗兰酮的25%和1.0%,反应10 h,5-氧代-α-紫罗兰酮的产率达53.4%,反应转化率达95.0%以上,平行实验表明,实验重复性良好。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.