Electroorganic synthesis of catecholthioethers

[reaction: see text] It is demonstrated that o-quinones, generated by the electrochemically driven oxidation of the catechols (1a-d) at physiological pH, are rapidly scavenged by 2-mercaptobenzoxazole (3) to give related catecholthioethers (4a-d) via an EC electrochemical mechanism pathway. The electrochemical syntheses of 4a-d have been successfully performed in one-pot in ambient conditions and in an undivided cell using an environmentally friendly method with high atom economy.     

Determination of ternary mixtures of penicillin G, benzathine and procaine by liquid chromatography and factorial design study

In the present work, a rapid and sensitive method for simultaneous determination of penicillin G (PG), benzathine (BE) and procaine (PR) in drug and serum media is introduced. The polar hydro-organic (55/45) mobile phases containing an aqueous solution adjusted to pH = 3.7 and an organic solvent (MeOH) including triethylamine (TEA) and trifluroacetic acid (TFA) are used. The flow rate of 1 ml min⁻¹, a C₈ column (150 mm × 46 mm) with 5 μm i.d. and wavelength at 215 nm are selected for optimal separation condition. The limit of detection (LOD), linear concentration range and relative standard deviation (R.S.D.) of this method for the PG are 1.1 μg ml⁻¹, 10-2400 μg ml⁻¹ and 1.7% and for the BE are 1.2 μg ml⁻¹, 12-2100 μg ml⁻¹ and 1.8% and for the PR are 1.5 μg ml⁻¹, 20-2000 μg ml⁻¹ and 2%, respectively. The factorial design is used for the determination of main and interaction effects of pH, flow rate and concentration of MeOH, TEA and TFA in the separation at two levels. Also, the analysis of variance (ANOVA) table is obtained. The results show that TFA and TEA have higher effect than concentration of MeOH, pH and flow rate factors.     

Electrochemical synthesis of quinones and other derivatives in biphasic medium

Electrochemical synthesis of quinones has been attempted from phenols, 1,4-dihydroxybenzenes, 1,4-dihydroxynaphthalenes and related compounds using biphasic media. Excellent yields of quinones (98%) or brominated diols have been achieved with good current efficiency. Reuse of the electrolyte without any modification and quantitative conversion of substrate with theoretical amount of current are the advantages of this method.     

Electroorganic synthesis of 6-aminonicotinic acid from 2-amino-5-chloropyridine

A synthesis of 6-aminonicotinic acid by electrochemical hydrogenation of 5-chloro-2-nitropyridine and electrochemical carboxylation of 2-amino-5-chloropyridine at a cathode surface in the presence of sulphuric acid and carbon dioxide in a dimethylformamide (DMF) solution at an apparent current density of 10 mA/cm² using an undivided cell with good yields is reported.     

Electroorganic synthesis. Reductive alkylation of functionalized 1,2-dithiole-3-thiones

Two-electron reduction of some substituted 1,2-dithiole-3-thiones 1 followed by alkylation of the dianionic intermediates leads through electrosynthesis to mixture of Z and E isomers of the corresponding substituted alkyl-(3-thioalkyl)-2-propenedithioates 2, 3 in satisfactory yield. The structure of those products was established by ¹³C and ¹H nmr and mass spectroscopy. The isomers ratios were determined by nmr spectroscopy.     

Electroorganic synthesis of new benzofuro[2,3-d]pyrimidine derivatives

Electrochemical oxidation of 3,4-dihydroxybenzoic acid (1) in the presence of 1,3-dimethylbarbituric acid (2) and 1,3-diethyl-2-thiobarbituric acid (3) as nucleophiles in aqueous solution has been studied using cyclic voltammetry and controlled-potential coulometry. The results indicate that 1 via Michael reaction under electro-decarboxylation reaction converts to benzofuro[2,3-d]pyrimidine derivatives (6a, 6b). The electrochemical synthesis of 6a, 6b has been successfully performed in an undivided cell in good yields and purity.     

硝基苯在铜电极上的电还原特性研究

应用循环伏安法和线性扫描伏安法研究水溶液中硝基苯在铜电极上的电还原特性及其电还原为苯胺的中间步骤和反应机理.结果表明:铜电极上硝基苯的还原电位在-0.58V和-1.32V左右(vs.SCE),溶液的酸性和碱性均有益于该还原反应的发生;还原过程伴有反应物吸附现象,当硝基苯浓度较大时,还原过程受传质过程控制;随着厌氧程度的提高,还原速率加快.     

Recent Progress on Two-dimensional Electrocatalysis

Due to their unique electronic and structural properties triggered by high atomic utilization and easy surface modification, two-dimensional(2D) materials have prodigious potential in electrocatalysis for energy conversion technology in recent years. In this review, we discuss the recent progress on two-dimensional nanomaterials for electrocatalysis. Five categories including metals, transition metal compounds, non-metal, metal-organic framework and other emerging 2D nanomaterials are successively introduced. Finally, the challenges and future development directions of 2D materials for electrocatalysis are also prospected. We hope this review may be helpful for guiding the design and application of 2D nanomaterials in energy conversion technologies.     

Electrochemical synthesis and study of coordination compounds part 1: tin(II) catechol complexes

The electrochemical synthesis of tin(II) complexes of catechols, Sn(O₂Ar) (1a–9a), have carried out using tin metal as a sacrificial anode in acetonitrile, in the presence of catechol derivatives. The cyclic voltammetric characteristics of the synthesized complexes Sn(O₂Ar) (1a–9a) have been studied at glassy carbon electrode in dichloromethane. Anodic oxidation of Sn(O₂Ar) produces a single wave which shows irreversibility. Also, the electronic effects of ligands on the redox potential of complexes 1a–9a have been investigated. The synthesis of Sn(O₂Ar) species in high yields and purity has been successfully performed in an undivided cell using constant current conditions.     

Electrochemical Co-reduction of Bi(Ⅲ)and Y(Ⅲ)and Extracting Yttrium from Molten LiCl-KCl Using Liquid Bi as Cathode

The electrochemical reaction of Bi(Ⅲ)and co-reduction behaviour of Bi(Ⅲ)and Y(Ⅲ)ions were researched in molten LiCl-KCl on a ttmgsten(W)electrode employing a range of electrochemical teclmiques.Cyclic voltammetric and square-wave voltanunetric results revealed that the reduction of Bi(Ⅲ)was a one-step process,with the exchange of three electrons on a W electrode,and diffusion-controlled.The electrochemical curves showed two reduction peaks pertaining to the formation of Bi-Y alloy compounds,because of the co-reduction of Bi(Ⅲ)and Y(Ⅲ) by metallic Y deposited on the pre-deposited Bi-coated W electrode and reacting with Bi metal in molten LiCl-KCl. Furthermore,galvanostatic electrolysis was conducted using liquid Bi as cathode to extract yttrium at different current intensities,and the extractive products were analyzed by SEM,EDS and XRD.The results indicated that BiY intermetallic compotmd was formed in the molten LiCl-KCl-YCl3 system.     

低温煤焦油电解加氢性能的研究

对电极材料、溶剂种类、支持电解质种类等的选择、低温煤焦油在间歇式卫离电解槽中，以铅板为阴极，、铂丝为阳极，以ＤＭＦ＝Ｃ２Ｈ３ＯＨ－Ｈ２Ｏ－Ｂｕ４ＮＢｒ为电解体系，电解后可得到较争孤加氢效果，当ＤＭＦ：Ｃ２Ｈ５ＯＨ＝２：３（体积比），「Ｈ２Ｏ」＝２．５ｍｏｌ／ｌ，「Ｂｕ４ＮＢｒ」＝０．５０ｍｏｌ／ｌ，Ｔ＝３０６Ｋ，电解电位为－２．２Ｖ，电解后的焦油中氢含量可提高０．８４％，Ｈ／Ｃ原子比可增加０．１５     

MFC逆转化CO2合成甲醇研究

微生物燃料电池(MFC)反应器是利用附着在阳极上的产氢微生物,在吸收烟气CO2的同时将CO2逆转化合成高附加值的生物合成燃料的装置。试验选用从牛粪中分离筛选出的梭状芽孢菌(Clostridium.sp)作为合成生物燃料的合成菌,将MFC反应装置接入电化学工作站进行CV测试,当发生还原反应时,在-0.5 V时出现还原峰,利用直流稳压电源恒电压电解,检测到合成的生物燃料为甲醇。在24 h时甲醇的积累量达到最大3.13 mmol/L;当CO2气体比例为15%时甲醇积累量最大,为2.98 mmol/L。在细菌接种量为1 mL时,甲醇积累量达到最大,为2.76 mmol/L。,最适条件下的CO2转化率为7.5%。     

Electroorganic synthesis using a fluoride ion mediator under ultrasonic irradiation: synthesis of oxindole and 3-oxotetrahydroisoquinoline derivatives

[reaction: see text] Anodic intramolecular cyclization of alpha-(phenylthio)acetamides using a fluoride ion mediator was realized. Under ultrasonic irradiation, cyclization was accelerated markedly to give desired cyclized products in moderate to good yields. The local heating effect of ultrasonic irradiation seems to be more advantageous than usual heating.     

煤沥青的电化学加氢：Ⅲ.中间相沥青的电化学加氢

在隔离式电解槽中，以泡沫铅作阴极，铂作阳极，饱和甘汞电极作为参考电极，以ＤＭＦ＋ＥｔＯＨ＋Ｈ２Ｏ＋Ｂｕ４ＮＢｒ作电妥体系，对太原钢铁公司焦化厂煤沥青为原料制得的中间相沥青进行了电化学加氢的研究，考察了电解电位，温度，溶剂浓度等对国氢的影响。     

电辅基在有机电合成中的应用

对近年来电辅基在有机电合成中的应用研究概况进行了综述。电辅基共分为两 大类，第一类电辅基是由第四主族的无素参与组成的有机基团，而有机硫基团属于 第二类电辅基。电辅基可以使分子的最高占有轨道（HOMO）的能量升高，促进电子 的传递，从而降低有机底物的氧化电势，使碳原子与电辅基相连化学键选择性地断 裂，同时接受亲核试剂的进攻，使反应的选择性提高。电辅基在今后的有机化学合 成中具有广阔的应用前景。     

煤沥青的电化学加氢：Ⅱ.精制沥青的电化学加氢

在隔离式是电解中，用泡沫铅作用阴极，铂作阳极，饱和甘汞电极做参考电极，对太原钢铁公司焦化厂煤沥青经溶剂萃取后所得的精制沥青进行了电化学加氢的研究，考察了电解体系工艺条件对加氢效果的影响。     

Recent advances in paired electrolysis of biomass-derived compounds toward cogeneration of value-added chemicals and fuels

Pairing the electrocatalytic hydrogenation reaction with different anodic reactions driven by renewable electricity offers a greener way for producing value-added chemicals and fuels. In particular, replacing the sluggish water oxidation with a biomass-based upgrading reaction can reduce the overall energy cost, thus allowing for the simultaneous generation of high-value products at both electrodes. This mini-review summarized the recent progress in paired electrolysis of biomass-derived compounds, particularly the furanic chemicals. Some perspectives and outlooks were proposed for further improvements in this research area.     

Site directed nuclear bromination of aromatic compounds by an electrochemical method

Direct bromination of a wide range of aromatic compounds possessing electron-donating groups, such as methoxy, hydroxy or amino groups, have been carried out by two-phase electrolysis. This electrochemical method results in high yields (70-98%) of monobromo compounds and usually with high regioselectivity (>95%) for the para position.