Pub Date : 2023-12-08DOI: 10.2174/0122133356267427231120062925
Soumyadip Basu, C. Mukhopadhyay
This study incorporates the assembly of development methodologies of microwave-acti-vated protocol involving transition metal catalysts for the synthesis of numerous biologically im-portant heterocycles during the past few years. Herein, it highlights the potential of transition metal salts as catalysts in multicomponent reactions performed under microwave conditions for the for-mation of oxygen, nitrogen, and sulphur-containing bioactive heterocycle moieties. Microwave-activated organic synthesis has been well-utilized as an alternative to conventional methodology in pharmaceutical companies due to its potential to significantly improve the rate and consequently diminish the time span of the synthetic process. The traditional methods involving transition metal catalysts for synthesizing bioactive heterocyclic molecules are prolonged and, thus, difficult to meet the requirements for the timely supply of these important compounds. In our review, our main focus is on integrating such synthetic strategies involving transition metal catalysis with a microwave-activated multicomponent approach for developing bioactive heterocycles.
{"title":"Microwave-activated Synthetic Route to Various Biologically Important Heterocycles Involving Transition Metal Catalysts","authors":"Soumyadip Basu, C. Mukhopadhyay","doi":"10.2174/0122133356267427231120062925","DOIUrl":"https://doi.org/10.2174/0122133356267427231120062925","url":null,"abstract":"\u0000\u0000This study incorporates the assembly of development methodologies of microwave-acti-vated protocol involving transition metal catalysts for the synthesis of numerous biologically im-portant heterocycles during the past few years. Herein, it highlights the potential of transition metal salts as catalysts in multicomponent reactions performed under microwave conditions for the for-mation of oxygen, nitrogen, and sulphur-containing bioactive heterocycle moieties. Microwave-activated organic synthesis has been well-utilized as an alternative to conventional methodology in pharmaceutical companies due to its potential to significantly improve the rate and consequently diminish the time span of the synthetic process. The traditional methods involving transition metal catalysts for synthesizing bioactive heterocyclic molecules are prolonged and, thus, difficult to meet the requirements for the timely supply of these important compounds. In our review, our main focus is on integrating such synthetic strategies involving transition metal catalysis with a microwave-activated multicomponent approach for developing bioactive heterocycles.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"108 ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011233","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}
Pub Date : 2023-12-08DOI: 10.2174/0122133356264245231120053530
Omar Merino Pérez, Ricardo Cerón-Camacho, Rafael Martinez Palou
Lignin is a very abundant biopolymer with great potential to produce other high-value polymers with aromatic groups. Its valorization has been limited principally by its poor solubility in conventional organic solvents, which makes it difficult to deconstruct or transform it into other products with higher added value. In this work, we describe a one-pot procedure to prepare vari-ous Deep Eutectic Solvents and study their ability to dissolve Kraft lignin with the aid of micro-wave dielectric heating efficiently. Lignin is a widely available aromatic biopolymer that is largely discarded or used as a low-value fuel when separated in paper production processes, so researchers are engaged in the development of lignin dissolution processes that allow its easy deconstruction and transfor-mation into other products with higher added value. The main objective of this work is to find deep eutectic solvents capable of dissolving significant quantities of lignin with the aid of microwaves as a heating source. The present work developed a simple, fast, and efficient method to dissolve lignin using Deep Eutectic Solvent/acetonitrile as solvents and irradiation by dielectric microwave heating. Most of the DESs studied achieved significant dissolution of purchased lignin with com-mon organic solvents by employing microwave irradiation as the heating method. Some DESs studied in this work are good alternatives as solvents for lignin due to the solvent option of simple preparation from renewable precursors from biomass, such as glyc-erol, choline chloride, and urea, of low toxicity and cost for this application. The effectiveness of these systems appears to be based on molecular recognition by hydrogen bonding interactions involving the three species that make up the eutectic and the hydroxyl groups of the lignin. These solvents can be recovered and recycled.
木质素是一种非常丰富的生物聚合物,具有生产其他带有芳香基团的高价值聚合物的巨大潜力。木质素在传统有机溶剂中的溶解度较低,使其难以解构或转化为其他具有更高附加值的产品,从而限制了其价值的提升。在这项工作中,我们介绍了制备各种深共晶溶剂的一锅程序,并研究了它们在微波介电加热的帮助下高效溶解牛皮纸木质素的能力。木质素是一种广泛存在的芳香族生物聚合物,在造纸过程中分离出来后大多被丢弃或用作低价值燃料,因此研究人员致力于开发木质素溶解工艺,使其易于解构并转化为其他具有更高附加值的产品。本研究开发了一种简单、快速、高效的溶解木质素的方法,使用深共晶溶剂/乙腈作为溶剂,并通过介质微波加热进行辐照。所研究的大多数 DES 通过使用微波辐照作为加热方法,实现了用普通有机溶剂大量溶解所购买的木质素。这项工作中研究的一些 DESs 是木质素溶剂的良好替代品,因为这些溶剂可从生物质中的可再生前体(如甘油醇、氯化胆碱和尿素)中简单制备,毒性低且成本低。这些系统的有效性似乎是基于组成共晶的三种物质与木质素羟基之间的氢键相互作用所产生的分子识别。这些溶剂可以回收和循环使用。
{"title":"One-step Synthesis of Deep Eutectic Solvents and dissolution of their Kraft Lignin","authors":"Omar Merino Pérez, Ricardo Cerón-Camacho, Rafael Martinez Palou","doi":"10.2174/0122133356264245231120053530","DOIUrl":"https://doi.org/10.2174/0122133356264245231120053530","url":null,"abstract":"\u0000\u0000Lignin is a very abundant biopolymer with great potential to produce other high-value polymers with aromatic groups. Its valorization has been limited principally by its poor solubility in conventional organic solvents, which makes it difficult to deconstruct or transform it into other products with higher added value. In this work, we describe a one-pot procedure to prepare vari-ous Deep Eutectic Solvents and study their ability to dissolve Kraft lignin with the aid of micro-wave dielectric heating efficiently.\u0000\u0000\u0000\u0000Lignin is a widely available aromatic biopolymer that is largely discarded or used as a low-value fuel when separated in paper production processes, so researchers are engaged in the development of lignin dissolution processes that allow its easy deconstruction and transfor-mation into other products with higher added value.\u0000\u0000\u0000\u0000The main objective of this work is to find deep eutectic solvents capable of dissolving significant quantities of lignin with the aid of microwaves as a heating source.\u0000\u0000\u0000\u0000The present work developed a simple, fast, and efficient method to dissolve lignin using Deep Eutectic Solvent/acetonitrile as solvents and irradiation by dielectric microwave heating.\u0000\u0000\u0000\u0000Most of the DESs studied achieved significant dissolution of purchased lignin with com-mon organic solvents by employing microwave irradiation as the heating method.\u0000\u0000\u0000\u0000Some DESs studied in this work are good alternatives as solvents for lignin due to the solvent option of simple preparation from renewable precursors from biomass, such as glyc-erol, choline chloride, and urea, of low toxicity and cost for this application. The effectiveness of these systems appears to be based on molecular recognition by hydrogen bonding interactions involving the three species that make up the eutectic and the hydroxyl groups of the lignin. These solvents can be recovered and recycled.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"88 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011575","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}
Pub Date : 2023-12-04DOI: 10.2174/0122133356269940231116134734
Pranali Hadole, Sampat R. Shingda, Aniruddha Mondal, Kundan Lal, R. Chaudhary, Sudip Mondal
Microwave-assisted synthesis is a powerful tool in organic chemistry, providing a rapid and efficient method for the synthesis of bioactive heterocycles. The application of microwaves significantly reduces reaction times and increases percentage yields with high purity of the final product. To make the synthetic protocol greener, the application of the magnetic nanocatalyst is a rapidly growing area of interest nowadays. Magnetic nanocatalyst, with its unique features like magnetic separable facile recovery from the reaction media heterogeneously, makes the overall synthetic strategy cleaner, faster, and cost-effective. Aiming this, in the present review, we will focus on the infusion of Magnetic nanocatalyst to microwave-assisted synthesis of various classes of azaheterocyclic compounds, including pyridines, pyrimidines, quinolines, and benzimidazoles. The synthetic methodologies involved in the preparation of these heterocycles are highlighted, along with their biological activities. Furthermore, in this review, the most recent and advanced strategies to incorporate nanocatalysts in the microwave-assisted synthesis of natural products containing azaheterocyclic moieties in drug discovery programs are elucidated in detail, along with the incoming future scope and challenges
{"title":"Infusion of Magnetic Nanocatalyst to Microwave Propped Synthesis of\u0000Bioactive Azaheterocycles","authors":"Pranali Hadole, Sampat R. Shingda, Aniruddha Mondal, Kundan Lal, R. Chaudhary, Sudip Mondal","doi":"10.2174/0122133356269940231116134734","DOIUrl":"https://doi.org/10.2174/0122133356269940231116134734","url":null,"abstract":"\u0000\u0000Microwave-assisted synthesis is a powerful tool in organic chemistry, providing a\u0000rapid and efficient method for the synthesis of bioactive heterocycles. The application of microwaves significantly reduces reaction times and increases percentage yields with high purity of the\u0000final product. To make the synthetic protocol greener, the application of the magnetic nanocatalyst is a rapidly growing area of interest nowadays. Magnetic nanocatalyst, with its unique features like magnetic separable facile recovery from the reaction media heterogeneously, makes the\u0000overall synthetic strategy cleaner, faster, and cost-effective. Aiming this, in the present review,\u0000we will focus on the infusion of Magnetic nanocatalyst to microwave-assisted synthesis of various classes of azaheterocyclic compounds, including pyridines, pyrimidines, quinolines, and benzimidazoles. The synthetic methodologies involved in the preparation of these heterocycles are\u0000highlighted, along with their biological activities. Furthermore, in this review, the most recent\u0000and advanced strategies to incorporate nanocatalysts in the microwave-assisted synthesis of natural products containing azaheterocyclic moieties in drug discovery programs are elucidated in\u0000detail, along with the incoming future scope and challenges\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"19 10","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138601970","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}