一个绿色有机化学实验的推荐-3,4．二氢嘧啶-2（1H）-酮的绿色合成

文章结合笔者的科研经验,介绍了一个绿色有机化学实验。苯甲醛、乙酰乙酸乙酯和脲三组分在硝酸镧的催化下,经Biginclli反应绿色合成了6-甲基-4-苯基-5-乙氧羰基-3,4-二氢嘧啶．2（1H）．酮。与经典Biginelli反应相比,它具有条件温和、反应时间短、产率高和操作简单等优点。     

Nonisothermal Microwave Processing of Reaction-Bonded Silicon Nitride

The size and density of reaction-bonded silicon nitride (RBSN) specimens are limited by the reduction in pore size and pore volume associated with the nitridation reaction. In particular, under conventional heating, pores at the surface of dense compacts close before the center has reacted fully. Microwave heating offers a unique advantage over conventional heating for the processing of RBSN. A temperature gradient can be maintained within the compact, which causes the reaction to occur preferentially in the interior. This increases the amount of silicon converted to Si₃N₄ because the center of compacts with a high green density finishes reacting before the porosity near the surface closes. This study follows the reaction process and shows that partially nitrided silicon compacts have composition gradients in the radial direction. Microwave processing also facilitates control of the reaction rate.     

Ultrasound accelerated sulfonylation of amines by p-acetamidobenzenesulfonyl chloride using Mg–Al hydrotalcite as an efficient green base catalyst

The sulfonylation reaction of various aliphatic, alicyclic, aromatic, and hetero-aromatic amines with p-acetamidobenzenesulfonyl chloride has been investigated using different types of base catalysis under varied reaction conditions. Mg–Al hydrotalcite, characterizable as an inexpensive, reusable, and green solid catalyst, was found to be the most efficient catalyst, when the reaction is carried out in a minimum volume of solvent (acetone). The reaction was found to be accelerated drastically with the support of ultrasound irradiation, affording the sulfonamides in yields better or equivalent to those obtained under the longer lasting conventional stirring conditions.     

半导体颜料在伪装涂料中的应用研究

采用共沉淀法制备ATO和CdZnS半导体颜料,比较了制备出的半导体颜料与常见的单组分颜料涂层红外发射率大小。通过颜色混合规律将半导体颜料与着色颜料混合制备了绿色伪装涂料,制备出来的涂层具有较低的红外发射率,并且其光谱反射曲线满足美军标的光谱通道要求,具有较好的应用前景。     

载酶海藻酸钙复合微球稳定水包油型Pickering乳液及其强化界面酶催化反应

以疏水改性二氧化钛修饰的载酶海藻酸钙微球（E@Alg@s-TiO₂微球）稳定水包油（O/W）型Pickering乳液用于两相界面酶催化反应。与传统的两相游离酶体系相比,此体系以绿色、温和的方式将酶固定在乳液界面上,并强化了两相界面酶催化反应。研究成果归纳如下：油水比为1∶1.2时,Pickering乳液为O/W型;E@Alg@s-TiO₂微球浓度为3%（质量）时稳定效果最好,脂肪酶的负载量为15.8 mg·g^-1。以三丁酸甘油酯的水解反应为研究对象,该体系对油水体系的界面酶催化反应有很好的强化效果,具有96%转化率并提高酶活力7.8倍。重复使用5个批次能保留80%的酶活力。本研究进一步拓展了载酶海藻酸盐微球稳定的Pickering乳液体系的应用范围,有望为O/W体系的界面生物催化过程提供绿色平台。     

萘酚的催化合成技术进展

简述了近年来一元萘酚传统合成技术的发展,包括磺化碱熔法、异丙萘法、水解法、四氢化萘法。重点介绍了一元萘酚绿色化合成工艺研究的新进展,特别是直接催化合成法和生物工程法的机理、工艺。最后对直接催化合成法的发展前景做了展望。     

First Gewald reaction ignited by sodium polysulfide: greener ultrasound-promoted synthesis of substituted 2-aminothiophenes in the absence of catalyst

In this paper, a modified and facile Gewald reaction triggered by sodium polysulfide in the absence of catalytic base was developed. This approach involves a one-pot ultrasound-irritated aqueous reaction between ketones or aldehydes, malononitrile, and sodium polysulfide, which are converted into the corresponding 2-aminothiophene derivatives in moderate to high yields. In comparison with conventional methods, the prominent features of this sonocatalyzed procedure are experimental simplicity, good functional group tolerance, atom efficiency, and the use of water as a green solvent.     

双氧水绿色合成工艺的研究进展

简述了双氧水的技术发展过程,分析了双氧水现有合成工艺的特点及其不足,介绍了以超临界二氧化碳作为反应介质的双氧水新型绿色合成工艺,重点阐述了新工艺中采用的亲二氧化碳催化剂及其研究进展.     

Fast and efficient green synthesis of thiosulfonate S-esters by microwave-supported permanganate oxidation of symmetrical disulfides

Potassium permanganate absorbed on copper(II) sulfate pentahydrate has been found to be an efficient, inexpensive, and green oxidation agent for the synthesis of “symmetrical” thiosulfonate S-esters by oxidation of the corresponding symmetrical disulfides. The oxidation reactions were carried out under solvent-free reaction conditions within 15?min under the influence of microwave irradiation, as well as (for comparison) supported by conventional heating, to afford yields of the thiosulfonate S-esters in the range of 60–83%. The oxidation reaction appears to proceed (at least partly) via an intermediate symmetrical vic-disulfoxide.     

Microwave induced reactive base wash for the removal of oxidation debris from carboxylated carbon nanotubes

Removal of oxidation debris for generating high purity functionalized carbon nanotubes (CNTs) has been a challenge, where base washing has been found to be an effective purification treatment. In this paper we report microwave induced reactive base wash (MRW) as a fast, green alternate to conventional filtrate washing. Carboxylated CNTs of three different dimensions were subjected to MRW and the results were compared to conventional base-wash. The results showed that MRW was an effective method for the removal of oxidation debris which reduced the reaction time from 4 h to 20 min and alkali consumption by 75%. The CNTs from MRW were similar to those from conventional base wash in terms of dimensions, elemental composition, BET surface area and colloidal stability in aqueous media.     

Effects of Green Density on Crystallization and Mullitization in the Transiently Sintered Mullite

The effects of green density as an experimental parameter in influencing the crystallization of an amorphous silica layer coated on the surface of α-alumina powder particles and the subsequent reaction of crystalline cristobalite and alumina to form mullite have been investigated. Green compacts consisting of alumina powder particles coated with an amorphous silica layer were fabricated using both a conventional uniaxial die pressing and rotary forging at room temperature, resulting in various green densities from 15% to 68% theoretical density. It has been shown that both the crystallization temperature of the amorphous silica layer coated on the surface of alumina powder particles and the subsequent mullitization temperature are lowered in the highly compacted materials.     

麻保沙星的合成工艺研究

介绍了一种麻保沙星的绿色合成工艺。以2,3,4,5-四氟苯甲酸为原料,经酰氯化后与3-(N-甲基-甲酰肼基)-丙烯酸乙酯偶联、环合,与4-甲基哌嗪缩合、水解、环合,氨水中和得到目标产物,总收率为47.7%。与传统工艺相比,该法原料易得,实验步骤少,收率高,操作简单,具有一定的工业化前景。     

Supercritical carbon dioxide as a green reaction medium for catalysis

Carbon dioxide in its liquid or supercritical state (scCO(2)) has a prodigious potential as an environmentally benign reaction medium for sustainable chemical synthesis. Since the mid-1990s, rapidly increasing research efforts have shown that scCO(2) can replace conventional and potentially hazardous solvents in a wide range of processes. There is also increasing evidence that the application of scCO(2) can broaden the scope of catalytic synthetic methodologies. On the basis of the experience in our laboratories, this report analyzes the impact of scCO(2) on green organometallic catalysis.     

Reversible luminescence modulation of Ho‐doped K0.5Na0.5NbO3 piezoelectrics with high luminescence contrast

A significant luminescence modulation behavior based on photochromic reactions was observed in Ho³⁺‐doped (Na_0.52K_0.48)_0.92Li_0.08NbO₃ ceramics, fabricated by the conventional solid‐state reaction method. Under visible light irradiation (407 nm) for 20 second, the samples changed pale gray from initial pale green, and returned to their original color by a thermal stimulus of 230°C for 10 minutes, showing typical photochromic phenomenon. Under 453 nm excitation, the samples exhibited strong green emission at 551 nm. Interestingly, their green emission intensity can be effectively tailored by controlling photochromic reaction processes (irradiation wavelength and time), and the luminescent modulation ratio (ΔR_t) reaches up to 77%. And, the ΔR_t value has no any obvious degradation after 10 cycles by alternating visible light irradiation and thermal stimulus, showing excellent reversibility. These results make it potential applications in many fields as a kind of multifunctional material.     

RETRACTED ARTICLE: Enzyme performance in ionic liquids

Ionic liquids (ILs) having unique properties such as no measurable vapor pressure, nonflammability and a wide temperature range of liquid phase have been recognized as potential green solvents. As a result, ILs have been extensively explored as reaction media for various biocatalytic reactions over a decade. Enzyme activities in ILs are generally comparable with or higher than those observed in conventional organic solvents. Furthermore, enhanced thermal and operational stabilities and regio- or enantioselectivities have been observed in many cases. Thus, ILs offer new possibilities for the application of solvent engineering to biocatalytic reactions. This review discusses the effect of physicochemical properties of ILs on biocatalysis with respect to enzyme activity, stability and selectivity by systematizing literature data on enzyme-catalyzed reaction in ILs.     

Controlled Firing of Reaction-Bonded Aluminum Oxide (RBAO) Ceramics: Part II, Experimental Results

The reaction-bonded aluminum oxide (RBAO) process is an attractive alternative to conventional processing of ceramics, because of advantages such as lower costs, enhanced green machinability, near-net-shape forming, and broad microstructural variability. However, various problems are still encountered in the production of RBAO ceramics. Part I of the paper presented model predictions that may allow for the controlled firing of RBAO ceramics. The current work investigates the reaction behavior of RBAO ceramics under the model-predicted conditions (i.e., for varying oxygen content, heat loss, heating cycles, and scale) via thermogravimetry, differential thermal analysis, and analysis of samples that have been fired in a box furnace. By controlling the reaction, one can produce large, crack-free RBAO ceramics.     

低共熔溶剂在电池和电催化中的应用

绿色且高效的电池和电催化反应是可持续发展的基本要求,其关键因素之一在于选择能提高效率的绿色电解质和合成高效电极材料的绿色溶剂。低共熔溶剂（DESs）是一种新型环境友好的电解质和溶剂。与传统的溶剂和电解质（如离子液体、水、超临界二氧化碳）相比,DESs具有合成简便、价格低廉、可设计等优点,在电池和电催化领域有着广阔的应用前景。这方面的研究还处于起步阶段,未见有综述系统介绍。本综述内容包括以下几个部分。（1）DESs作为电池和电催化反应的电解质,其中电池包括太阳能电池、锂离子电池、钠电池、锌电池、铝电池、液流电池、超级电容器,电催化反应包括析氧反应、析氢反应、氧还原反应、全解水反应、氮气电催化反应、二氧化碳电还原反应;（2）DESs作为制备电池和电催化反应电极材料的溶剂;（3）DESs作为回收电极材料的溶剂;（4）结论和展望。     

Ionic liquid catalyzed synthesis of organosoluble wholly aromatic optically active polyamides

A series of optically active wholly aromatic polyamides (PAs) with amino acid moieties in the pendant groups have been synthesized through polycondensation of a chiral diacid and aromatic diamines in an ionic liquid (IL) as a green, safe and eco-friendly medium and also reactions catalysis agent (method I). Furthermore, the polymerization reactions were performed via conventional polycondensation (method II) and obtained results have been compared. Evaluation of data shows that IL is the better polyamidation medium and catalysis stand on the higher inherent viscosities and yields of the obtained PAs and the rate of polymerizations beyond the greener reaction conditions and deletion of some essential reagents in conventional manners. Characterization were performs by means of ¹H-NMR and FT-IR spectroscopy, elemental analysis, thermogravimetric analysis and differential scanning calorimetric techniques.     

High Regioselective Diels–‐Alder Reaction of Myrcene with Acrolein Catalyzed by Zinc‐Containing Ionic Liquids

The ambient zinc‐containing ionic liquids, MX‐ZnCl₂, functioning as both Lewis acid catalyst and green solvent, are employed for a high regioselective Diels–Alder reaction of myrcene with acrolein for the first time, where MX is either 1‐butyl‐3‐methylimidazolium chloride (BmimCl), 1‐ethyl‐3‐methylimidazolium bromide (EmimBr), N‐butylpyridinium bromide (BPyBr), or N‐ethylpyridinium bromide (EtPyBr). Compared with the analogous reaction performed over a ZnCl₂ catalyst in the conventional solvent dichloromethane, higher regioselectivity of the ‘para’ cycloadduct and excellent yield were achieved at shorter reaction time in these ionic liquids with optimized molar compositions of MX and ZnCl₂. These moisture‐insensitive ionic liquids can be easily separated from reaction products after simple washing with hexane, allowing their reuse with no obvious loss in activity.     

纤维素在离子液体溶剂中溶解性能的研究进展

离子液体以其熔点低、蒸气压小、酸性可调及良好的溶解性能、黏度、密度等优异的理化特性成为纤维素的新型溶剂。离子液体与传统的纤维素溶剂相比,具有低挥发性、可回收利用、热性质稳定的优点,避免了有机溶剂所造成的污染。介绍了纤维素在离子液体溶剂体系中的溶解、再生和衍生的研究进展。