微波辐射在无溶剂有机合成中的应用

介绍了微波辐射无溶剂有机合成及其优点。     

氧杂蒽酮类化合物的合成研究进展

氧杂蒽酮类化合物具有广泛的药理活性,是一种重要的有机合成中间体。本文综述了近几年来氧杂蒽酮类化合物的合成方法,主要包括微波辐射法、无溶剂研磨法、催化剂法、离子液体法等。     

微波有机合成及反应器研究新进展

综述了近年来微波辐射技术在有机合成应用中的新进展。针对微波有机合成反应技术及专用微波反应器作了重点介绍。     

微波辐射技术在氮杂环化合物中的应用

微波辐射有机合成反应由于其操作简便、节能环保、后处理简单等优点,广泛应用于有机合成中,特别是杂环化合物中。本文评述了微波辐射技术在氮杂环化合物的合成中的应用。     

微波促进有机合成化学的应用进展

综述了近年来微波辐射技术在有机合成中的应用。探讨了微波辐射有机反应中的作用原理。并展望了微波促进有机化学的发展前景。     

微波在有机合成中的应用

综述了微波技术在有机合成中的应用。着重介绍波辐射反应的特点及其在重要有机合成反应中应用的进展。     

微波法合成正丁醚

利用Discover微波精确有机合成系统,采用单模聚焦微波辐射技术及电脑微控和空压气体同步冷却技术,研究了在催化剂作用下以正丁醇合成正丁醚的反应.考察了在Discover微波精确有机合成系统下微波功率、辐射时间、催化剂用量等对转化率的影响.通过实验确定了最佳工艺条件:正丁醇31 mL,催化剂4.5 mL,微波辐射时间为13 min,最大功率为150 W.产品经傅里叶红外光谱仪表征,证实与目标产物完全一致.     

微波辐射在有机合成反应中的发展和应用

本文介绍了微波辐射技术在有机合成中的发展和应用并列举了一些近期发展起来的微波反应器技术。     

微波辐射下无溶剂合成季戊四醇双缩苯甲醛

在微波辐射下用硫酸铝钾催化无溶剂合成了季戊四醇双缩苯甲醛.考察了微波辐射时间、微波辐射功率、原料配比、催化剂用量对产率的影响.实验表明:当微波辐射功率为462 W,辐射时间为5 min,苯甲醛用量为30mmol,季戊四醇用量为15mmol,硫酸铝钾用量为0.3mmol时,产率可达83.3%.     

微波辐射在壳聚糖化学改性中的应用研究进展

微波辐射反应技术是近年来发展的新型有机合成制备方法,以其操作方便、低能耗、高产率和产品易纯化等特点而得到迅速发展。简要阐述了微波促进有机反应的原理,综述了近年来微波辐射技术在壳聚糖改性中的应用研究。     

Microwave-assisted organic synthesis and transformations using benign reaction media

A nonclassical heating technique using microwaves, termed "Bunsen burner of the 21st century", is rapidly becoming popular and is dramatically reducing reaction times. The significant outcomes of microwave (MW)-assisted green chemistry endeavors, which have resulted in the development of synthetic protocols for drugs and fine chemicals synthesis that are relatively more sustainable, are summarized. The use of emerging microwave-assisted chemistry techniques in conjunction with greener reaction media is dramatically reducing chemical waste and reaction times in several organic syntheses and chemical transformations. A brief historic account of our own experiences in developing MW-assisted organic transformations, which involve various benign alternatives, such as solid-supported reagents, and greener reaction media, namely, aqueous, ionic liquid, and solvent-free, for the synthesis of various heterocycles, coupling reactions, oxidation-reduction reactions, and some name reactions are described. Synthesis of Heterocycles. The synthetic chemistry community has been under increased pressure to produce, in an environmentally benign fashion, the myriad of heterocyclic systems required by society in a short span of time, and one of the best options to accelerate these synthetic processes is to use MW technology. The efficient use of the MW heating approach for the synthesis of various heterocyclic compounds in aqueous and solvent-free medium is discussed. Organic Named Reactions. The application of MW chemistry for various named reaction such as the Prins reaction, the Suzuki reaction, the Heck reaction, the Aza-Michael reaction, Trost's gamma-addition, and the Cannizzaro reaction are summarized. Synthesis and Application of Ionic Liquids. Ionic liquids (ILs), being polar and ionic, in character couple with MW irradiation very efficiently and are, therefore, ideal MW-absorbing candidates for expediting chemical reactions. MW-assisted solvent-free synthesis and application of ILs are discussed. Oxidation-Reduction Reactions. MW protocols using mineral oxides such as alumina, silica, and clay to immobilize reagents on such solid supports have been extensively explored under "dry" media conditions. Various solvent-free examples of oxidation reactions are discussed that involve mixing of neat substrates with clay-supported iron(III) nitrate (clayfen) or iodobenzene diacetate (IBD) as an oxidant; some interesting MW reduction protocols using borohydrides are also discussed. Protection-Deprotection Reactions. The protection and deprotection of alcohols and amines are common events in multistep organic syntheses. Various protection and deprotection protocols under MW irradiation are discussed, including tetrahydropyranylation and (benzyloxycarbonyl) (Cbz)-protection, which are the most frequently employed methods.     

Microwave and ultrasonic processing: Now a realistic option for industry

Environmentally friendlier preparations of chemical compounds and organic or inorganic materials are generally accompanied by the concept of saving resources by optimizing reaction conditions and/or introducing new process technologies. The use of ionic liquids and a solvent-free approach are among these technologies, but in terms of the minimisation of energy and optimization of reaction control both microwave and ultrasound irradiation have now proved to be real options. This review starts from the basic considerations on the separate interaction of microwaves and ultrasound with matter and goes on to explore some laboratory and industrial applications of each type of activation. It is also possible to enhance the effects of high frequency electromagnetic fields, typical of microwaves, or the cavitational energy associated with sonochemistry by combining them with other extreme conditions such as plasmas, high pressure and UV. Finally the simultaneous use of microwaves and ultrasound in a single reactor is described. This novel mixing of technologies has been implemented in order to combine the effects of enhanced energy with improved matter transportation.     

微波辐照法合成1,3-双（3-三乙氧基硅丙基）-咪唑氯鎓

比较了三种常规合成方法制备1,3-双(3-三乙氧基硅丙基)-咪唑氯鎓时，甲苯、乙腈做溶剂和无溶剂条件对产品收率的影响，认为溶剂极性较大和反应温度较高时更有利于反应的进行；同时，首次采用微波辐照法合成了1,3-双(3-三乙氧基硅丙基)-咪唑氯鎓，并考察了微波辐照功率、时间、投料比等对产品收率的影响；与常规合成方法相比，微波辐照合成1,3-双(3-三乙氧基硅丙基)-咪唑氯鎓具有反应时间短、收率高、不需要有机溶剂和操作方便等优点。该研究为快速、高效合成1,3-双(3-三乙氧基硅丙基)-咪唑氯鎓提供了新方法，为其他类似双硅烷化的有机硅前体的合成提供了新思路。     

Microwave Promoted Alkylation of Halonitrobenzene with Malonates in Solvent-free Medium

Abstract The alkylations on different substituted halonitro benzenes have been demonstrated with various malonates under the influence of microwaves irradiation. The reactions were catalyzed by potassium carbonate and benzyltriethylammoniumchloride. The salient features of this methodology are mild reaction conditions, high regio-selectivity, rapid conversions, solvent-free medium and easy isolation of products Graphical abstract Microwave Promoted Alkylation of Halonitrobenzene with Malonates in Solvent-free Medium Venkat Narsaiah Akkirala      

An Efficient Eco-Friendly Synthesis of Pyran Annulated Heterocyclic Systems under Conventional Heating and Microwave Irradiation in Solvent-Free Conditions

1,4-Diazabicyclo[2.2.2]octane (DABCO) has been used as an efficient and reusable solid base catalyst for the rapid and green synthesis of pyran annulated heterocyclic ring systems by the condensation reaction of various activated CH-acids and tetracyanoethylene under conventional heating and microwave irradiation in solvent-free conditions. Excellent yield, very short reaction time (2–5 min), operatinal simplity, easy work-up procedure, avoidance of hazardous or toxic catalysts, and organic solvents are the main advantages of this green methodology which makes it more economic than the other conventional methods.     

Synthesis of Condensed Benzo[N,N]-Heterocycles by Microwave-Assisted Solid Acid Catalysis

The synthesis of several types of condensed benzo[N,N]-heterocycles such as benzimidazoles, benzodiazepines, quinoxalinones by a microwave-assisted solvent-free solid acid catalyzed method is described. The commercially available, inexpensive K-10 montmorillonite is an excellent catalyst for the synthesis of the target compounds. Our approach is based on the reactions of a wide variety of o-phenylenediamines, with ketones, aldehydes and bifunctional reagents, respectively. The cyclization reactions were initiated by microwave irradiation. The products, in most cases, were obtained in very high yields (up to 98%) and excellent selectivities in very short reaction times. The effective combination of solid acid catalysis, solvent-free conditions and microwave irradiation provides an attractive and highly ecofriendly approach for the synthesis of these important heterocycles.     

Recent advances in microwave initiated synthesis of nanocarbon materials

This Feature Article focuses on the recent advances in synthesis of nanostructured carbon materials using microwave irradiation as the heating source. Although the microwave approach to chemical synthesis is relatively mature in organic synthesis, it is still in the early stage for nanomaterials synthesis, especially nanocarbons. Due to the energy efficient nature of microwave heating, there is a great opportunity to apply microwave irradiation to nanocarbon production, which normally requires high temperature, high vacuum or inert gas protections. Using microwave irradiation will give a green feature to the nanocarbon synthesis, since it offers high efficiency heating and fast carbonization. With our recent discovery, multi-walled carbon nanotubes can be synthesized through the microwave process even in air. Background about nanocarbons and microwave chemistry are introduced, the application of microwaves in synthesis of different types of nanocarbons is discussed and finally, the perspectives in the future research directions of microwave assisted nanocarbon synthesis are deliberated as well.     

微波辐射在多肽合成中的研究进展

微波作为一种可以加速有机反应的辅助技术已广泛地应用于多肽及其衍生物的合成。简要介绍了微波辐射加速有机反应的机理,综述了微波辐射在多肽及其衍生物合成中的最新研究进展,并展望了微波在多肽合成中的前景。     

New developments in polymer science and technology using combination of ionic liquids and microwave irradiation

The purpose of this review is to provide appropriate details concerning the application of ionic liquids (IL)s associated with microwave-assisted polymer chemistry. From the viewpoint of microwave chemistry, one of the key significant advantages of ILs is their high polarity, which is variable, depending on the cation and anion and therefore can effectively be tuned to a particular application. Hence, these liquids offer a great potential for the innovative application of microwaves for organic synthesis as well as for polymer science. ILs efficiently absorb microwave energy through an ionic conduction mechanism, and thus are employed as solvents and co-solvents, leading to a very high heating rate and a significantly shortened reaction time. Since an IL-based and microwave-accelerated procedure is efficient and environmentally benign, we believe that this method may have some potential applications in the synthesis of a wide variety of vinyl and non-vinyl polymers. This review describes application of combination of ILs with microwave irradiation as a modern tool for the addition and step-growth polymerization as well as modification of polymers and it was compared with ILs alone and conventional polymerization method.     

微波促进下新型离子液体催化的香豆素无溶剂合成研究

用新型的双磺酸型离子液体为催化剂,以乙酰乙酸乙酯和间苯二酚为原料,通过Pechmann反应在无溶剂条件下,用微波促进方式合成了香豆素,与传统方法相比,剔除了溶剂的使用,反应时间短,收率高,是一种环境友好的合成方法。