Current Microwave Chemistry最新文献

{"title":"Meet The Editorial Board Member","authors":"Elisabete Clara Bastos Do Amaral Alegria","doi":"10.2174/221333560801210603090602","DOIUrl":"https://doi.org/10.2174/221333560801210603090602","url":null,"abstract":"","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43372061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-assisted organic synthesis in Water","authors":"Geetanjali, Ram Singh","doi":"10.2174/2213335608666210623151121","DOIUrl":"https://doi.org/10.2174/2213335608666210623151121","url":null,"abstract":"\u0000\u0000Most of the traditional methods for organic synthesis have been associated with environmental concern. The transition from traditional to modern methods of synthesis is mainly based on principles of green chemistry to achieve better sustainability by reducing the negative impact on the environment and health. It has been found that microwaves as an energy source in organic synthesis have a great advantage over conventional heating. Microwave-assisted reactions are energy efficient and hence, brought themselves in the preview green chemistry principles. The use of safer solvents is another important principle of green chemistry. The use of water as a solvent in organic synthesis has great benefits over the use of hazardous organic solvents in terms of environment and safety. This study will cover the use of both microwave and water simultaneously in organic reactions.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45294305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and Pharmacological Activities of Oxadiazole and Pyrimidine Bearing Thiocoumarin Derivatives","authors":"Monika R. Tiwari, N. Patel","doi":"10.2174/2213335608666210401152153","DOIUrl":"https://doi.org/10.2174/2213335608666210401152153","url":null,"abstract":"\u0000\u0000The study aims to synthesize thiocoumarin scaffolds clubbed with pyrimidine\u0000and 1,3,4-oxadiazole ring system under microwave irradiation and describe their pharmacological\u0000activities.\u0000\u0000\u0000\u0000We report herein an efficient and simple Lewis acid-catalyzed procedure for the\u0000synthesis of novel series of thiocoumarin clubbed with pyrimidine and 1,3,4-oxadiazole motifs\u0000under microwave irradiation. The microwave-assisted technique has many advantages, such as a\u0000higher yield, a clean and selective procedure, shorter reaction time, and simple work-up.\u0000\u0000\u0000\u0000The objective of the present study is to design and synthesize thiocoumarin scaffolds\u0000clubbed with pyrimidine and 1,3,4-oxadiazole ring system by microwave-assisted heating. Our\u0000prime focus is to highlight the synthetic approach developed for the synthesis of heterocyclic moieties\u0000of pharmacological interest, and the prominence has also been given to distinct advantages\u0000provided by microwave heating.\u0000\u0000\u0000\u0000 Thiocoumarin clubbed with pyrimidine, and 1,3,4-oxadiazole motifs was synthesized\u0000under microwave irradiation. All the synthesized molecules were evicted by IR, 1H NMR, 13C\u0000NMR, and mass spectra. The anti-microbial activity of synthesized compounds was examined\u0000against two Gram-negative bacteria (E. coli, P. aeruginosa), two Gram-positive bacteria (S. aureus,\u0000S. pyogenes), and three fungi (C. albicans, A. niger, A. clavatus) using the MIC (Minimal Inhibitory\u0000Concentration) method, anti-tubercular activity H37Rv using L. J. Slope Method and anti-\u0000oxidant activity using DPPH and ABTS bioassay method.\u0000\u0000\u0000\u0000The application of microwave technology for the rapid synthesis of biologically significant\u0000thiocoumarin analogues is very promising because of its shorter reaction time and higher\u0000yield. Some of these new derivatives showed moderate to good in-vitro anti-bacterial, anti-fungal,\u0000and anti-tubercular activity. Compounds B4 and B7 appeared to have high radical scavenging efficacies\u0000as 35.32 ± 0.446 and 33.97 ± 1.069 μg/mL ± SD of IC50 values in DPPH and ABTS bioassay,\u0000respectively.\u0000\u0000\u0000\u0000Microwave-assisted synthesis provides an implicit way to discover a promising class\u0000of molecular entities for the development of new anti-microbial and anti-oxidant agents. Oxadiazole\u0000and pyrimidine bearing thiocoumarin derivatives showed improved anti-microbial, antitubercular,\u0000and anti-oxidant activity.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42220908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave Radiation Effects on the Acidic Properties of Fe/ZSM-5 Catalysts for Methanol Conversion","authors":"T. S. Ntelane, Themba E. Tshabalala, C. M. Masuku, M. Scurrell","doi":"10.2174/2213335608666210212103541","DOIUrl":"https://doi.org/10.2174/2213335608666210212103541","url":null,"abstract":"\u0000\u0000To use the microwave radiation as the post-treatment method to tune the acidic\u0000properties of Fe/ZSM-5 catalyst.\u0000\u0000\u0000\u0000ZSM-5 zeolite is a widely used standard catalyst in the methanol conversion to\u0000olefins and high-octane gasoline range hydrocarbons. However, the coke deposition and the concentration\u0000of acid sites determine its overall catalytic activity. Thus, the concentration of acid sites\u0000more precisely, the number of Brønsted acid sites, is vital in determining the activity of ZSM-5 zeolite\u0000and product distribution in the methanol-to-hydrocarbons reaction.\u0000\u0000\u0000\u0000(1) To modify ZSM-5 using an iron solution to form Fe/ZSM-5 via the impregnation\u0000method.\u0000\u0000(2) To tune the acidic properties of Fe/ZSM-5 using microwave radiation.\u0000\u0000(3) To check and determine the concentration of acidic sites using n-propylamine temperature-programmed\u0000surface reaction.\u0000\u0000(4) To check the effect of microwave radiation and acidic properties in the methanol conversion\u0000(product distribution) via methanol temperature-programmed surface reaction.\u0000\u0000\u0000\u0000Two sets of zeolites were used, with iron being introduced by ion-exchange from ferric\u0000nitrate (Fe(NO3)3 9H2O, Sigma Aldrich, ≥ 98% metal) solutions. These two series were designated\u0000as Z (0.5FeZ10/0-700) and X (0.5FeX10/0-700) after microwave treatment. The Z and X series possess the\u0000Si/Al framework ratio of 30 and 80, respectively. The TPSR studies were then conducted for characterization\u0000and catalytic tests.\u0000\u0000\u0000\u0000From the C3H9N-TPSR experiments, it was found that the concentration of Brønsted acid\u0000sites decreased with increasing microwave power level. Both X and Z series exhibited high selectivity\u0000to propene than ethene. Microwave treated catalysts (0.5FeZ10/280 and 0.5FeX10/462) with decreased\u0000concentration of Brønsted acid sites showed the highest propene/ethene ratios of 1.67 and\u00005.27, respectively.\u0000\u0000\u0000\u0000From the results obtained, it was found that the amount of methane evolved (as a measure\u0000of coke deposited) and the concentration of Brønsted acid sites decreased with increasing microwave\u0000power level (0-700 Watts). High selectivity to propene was found when using both X series\u0000(0.5FeX10/0-700) and Z series (0.5FeZ10/0-700) as catalysts. After decreasing the concentration of\u0000Brønsted acid using microwave treatment, the highest P/E ratios were observed for 0.5FeX10/280,\u00000.5FeX10/462, 0.5FeZ10/280 and 0.5FeZ10/462 catalysts.\u0000\u0000\u0000\u0000It is reasonable to suggest that microwave radiation could be a feasible post-synthesis modification\u0000step to produce ZSM-5 based catalysts that exhibit reduced concentration of Brønsted acid sites, reduced\u0000methane formation, increased catalytic activity and selectivity.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47198010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-Assisted Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones Using Acid-Functionalized Mesoporous Polymer","authors":"Bishwajit Changmai, K. Rajkumari, D. Das, Lalthazuala Rokhum","doi":"10.2174/2213335608666210329130736","DOIUrl":"https://doi.org/10.2174/2213335608666210329130736","url":null,"abstract":"Synthesis and application of acid-functionalized mesoporous polymer catalyst for the synthesis of\u00003,4-Dihydropyrimidin-2(1H)-ones via Biginelli condensation reaction under microwave\u0000irradiation is investigated. Several analytical techniques such as FT-IR, BET, TEM, SEM and EDX\u0000were employed to characterize the synthesized polymeric catalyst. High acidity (1.15 mmol g-1\u0000),\u0000high surface area (90.44 m2\u0000g\u0000-1\u0000) and mesoporous nature of the catalyst effectively promoted the\u0000synthesis of 3,4-Dihydropyrimidin-2(1H)-ones. Microwave irradiation shows higher yield (89-98\u0000%) as compared to conventional heating (15-25 % yield) under our optimized reaction conditions\u0000such as 1:1:1.2 molar ratio of aldehyde/ethylacetoacetate/urea, catalyst loading of 6 wt.% (with\u0000respect to aldehyde), the temperature of 80 °C and microwave power of 50 W. The synthesized\u0000Biginelli products were fully characterized by 1H and 13C NMR. The reusability of the catalyst\u0000was investigated up to 5 successive cycles and it showed great stability towards the synthesis of\u00003,4-Dihydropyrimidin-2(1H)-ones without any significant depreciation in yields.","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45219211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-assisted Claisen Rearrangement of 1-Allyloxy-4-hydroxybenzene in the Presence of Metal Salt","authors":"Fumiyoshi Ozaki, Y. Okada","doi":"10.2174/2213335607666210106094449","DOIUrl":"https://doi.org/10.2174/2213335607666210106094449","url":null,"abstract":"\u0000\u0000Microwave-assisted Claisen rearrangement of allyloxybenzene with a hydroxyl group\u0000was conducted in the presence of metal salts. The rearrangement was promoted in the presence of\u0000an alkali metal salt, because the reaction substrate was converted into a phenoxide-type ion, which\u0000can efficiently absorb microwaves. In contrast, a Lewis acid was strongly coordinated to the ethereal\u0000oxygen, and this structure could also absorb microwaves efficiently.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48616658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of Novel Microwave-Convective Drying on the Functional Properties of Dried-Pears (Pyrus communis)","authors":"G. Yildiz","doi":"10.2174/2213335607999201231212208","DOIUrl":"https://doi.org/10.2174/2213335607999201231212208","url":null,"abstract":"\u0000\u0000The objective of this study was to investigate the impacts of combined microwave-\u0000convective drying on the quality of dried-pears. Color, bioactive compounds (total\u0000phenolics (TP) and antioxidant capacity (AC)) and textural (hardness) properties of convective (50\u0000and 60 °C), microwave (100 and 200 W), and combined microwave-convective (100-50 °C,\u0000200W-50 °C, 100 W-60 °C and 200 W-60 °C) dried pears were compared with the untreated pears.\u0000\u0000\u0000\u0000A Konica Minolta CR-400 Chroma Meter was used to examine the color\u0000changes in dried pears. TP was measured using the Folin-Ciocalteu reagent. The free radical scavenging\u0000activity of the extract was analyzed using 1,1-dipheyl-2-picylhydrazyl (DPPH). The hardness\u0000of dried pear slices with different drying methods was obtained by a texture analyzer. The microwave-\u0000convective dried pear slices (especially at the condition of 200 W - 60 °C) showed higher\u0000preservation of bioactive compounds in addition to improved textural properties and color compared\u0000to other dried pear samples.\u0000\u0000\u0000\u0000Overall, combined microwave-convective drying is a promising process, as demonstrated\u0000in current research by its capability to better retain dried pear quality in terms of functional\u0000and textural properties.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46251736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review of Microwave Synthesis of Zirconia Composite Ceramics","authors":"Yeqing Ling, Qiannan Li, Hewen Zheng, M. Omran, Zhi Yang","doi":"10.2174/2213335607999201231212005","DOIUrl":"https://doi.org/10.2174/2213335607999201231212005","url":null,"abstract":"\u0000\u0000As a new technology for preparing zirconia materials, microwave-assisted technology\u0000has been widely concerned in recent years. In this paper, the microwave-assisted method and its application\u0000in the preparation of inorganic materials are briefly described. The research progress of\u0000the preparation of zirconia by microwave-assisted method is reviewed. Some problems existing in\u0000the research status are pointed out, and the application prospect in this field is prospected.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43489758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meet Our Editorial Board Member","authors":"Juan Carlos Castillo Millán","doi":"10.2174/221333560703201211090723","DOIUrl":"https://doi.org/10.2174/221333560703201211090723","url":null,"abstract":"","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42373585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research Status of Microwave-assisted Reduction Technology of Pyrolusite","authors":"Li Qiannan, Li Yeqing, Zheng Hewen, Yang Zhi","doi":"10.2174/2213335607999201222095248","DOIUrl":"https://doi.org/10.2174/2213335607999201222095248","url":null,"abstract":"\u0000\u0000Manganese ore is an important metallurgical raw material that holds an important strategic\u0000position in the national economy of China. However, the grade of manganese ore in the country\u0000is mostly low, and the utilization efficiency of low-grade manganese ore resources is low, which seriously\u0000restricts the healthy and stable development of China’s metallurgical industry. As a new\u0000green heating method, microwave is expected to address the problems of conventional methods\u0000and realize the effective utilization of low-grade manganese ore. In this paper, the research status\u0000of the microwave composite reduction of pyrolusite in recent years is reviewed. Microwave plays\u0000an important role in metallurgy, and it is the current direction pursued to improve the research level\u0000of microwave heating and extend it to actual industrial processes.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42584090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}