S. Anas, Shajahan Rubina, Sarang Rithwik, Ramakrishnan Roopak
{"title":"Recent advances in polymer-supported proline-derived catalysts for asymmetric reactions","authors":"S. Anas, Shajahan Rubina, Sarang Rithwik, Ramakrishnan Roopak","doi":"10.2174/2213337210666230224115814","DOIUrl":"https://doi.org/10.2174/2213337210666230224115814","url":null,"abstract":"\u0000\u0000The last two decades have witnessed tremendous growth in organocatalysis, especially using proline and related catalysts in a wide range of organic processes. Along with this, the heterogenization of organocatalysts over suitable support systems also emerged as an effective approach for addressing some of the major drawbacks associated with classical organocatalysts. Polymer-immobilized catalysts, in particular, are extremely stable under reaction conditions with excellent recyclability and reusability. Moreover, this approach offers green chemistry standards and is, thereby, supportive of large-scale industrial manufacturing processes. This article summarises the developments using polymer immobilized proline-derived systems as efficient organocatalysts for various asymmetric transformations in Aldol, Michael, Mannich, cyclization reactions, etc.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44884318","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 Greener Synthetic Approach to Tetrazoles via Multicomponent Reactions","authors":"D. Ray","doi":"10.2174/2213337210666230222093637","DOIUrl":"https://doi.org/10.2174/2213337210666230222093637","url":null,"abstract":"\u0000\u0000The synthesis of heterocyclic compounds has drawn considerable attention in the scientific community due to their existence in the majority of medicinal & pharmaceutically important compounds as well as natural products. Among them, the remarkable existence of tetrazoles has been realized in several commercially available drugs. In this regard, various synthetic protocols to access tetrazoles have been developed to address the efficiency and environmental impacts in terms of minimization of the steps, elevating yields, and conducting environmentally benign and sustainable chemistry. The management and detrimental environmental impact of waste has been recognised as a consistent concern, along with the costs associated with its disposal. Among various approaches to minimise unwanted materials from a process, one of the best alternatives is to perform a reaction in the absence of excess chemical reagents and catalysts. Other options include the reactions affected by the application of heat, light, sound, or electrolysis. The multicomponent reactions (MCR) display a unique approach establishing a step forward toward clean, step and atom-economical chemical synthesis. Most of them utilize the required substrates, eliminating the stoichiometric use of reagents, reducing the possibility of forming unwanted side products. The present review displays the concepts of MCR in the synthesis and functionalization of tetrazole, which contributes to green and sustainable chemistry.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48529939","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":"Organocatalytic C-H Bond Functionalizations for the Synthesis of Heterocycles","authors":"Biswajit Panda","doi":"10.2174/2213337210666230213120833","DOIUrl":"https://doi.org/10.2174/2213337210666230213120833","url":null,"abstract":"\u0000\u0000Organocatalysis is an important and rapidly growing area for the synthesis of various organic molecules. Because of the inherent non-metal properties, mild reaction conditions, and broad functional group tolerance, the use of small organic compounds encoding and converting another organic component has developed into a remarkable process. C–H activation reactions, on the other hand, have already emerged as a powerful strategy for forming C–C and C–X (X= N, O, S) bonds. Combining organocatalysis and C-H bond functionalization is highly rational as two coexisting and rapidly growing research fields in modern synthetic chemistry, and the cooperative strength along this consistent has proven to be a successful way of making C-H bond functionalization much more feasible, reliable, and specific. At the same time, the synthesis of heterocyclic compounds is an important field in organic chemistry due to the vast application of heterocycles in pharmaceuticals, polymers, and material science. This mini-review describes the recent developments in the synthesis of heterocyclic compounds through the alliance of organocatalysis and C-H bond functionalizations.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47624712","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":"Greener Approaches towards 1,4–Benzothiazine Synthesis: Recent Updates and Outlook","authors":"B. Basu, Suchandra Bhattacharya","doi":"10.2174/2213337210666230213144211","DOIUrl":"https://doi.org/10.2174/2213337210666230213144211","url":null,"abstract":"\u0000\u0000Heterocyclic moieties are ubiquitous in nature and the exploration of heterocyclic chemistry goes centuries back , which have coalesced into the invention of greener methodologies towards the synthesis of heterocycles of potential uses. Benzothiazine is an important class of heterocyclic molecule, in which a benzene ring is fused with a six–member N, S containing ring. Amongst the three possible isomers, 1,4–benzothiazines show a wide spectrum of pharmaceutical and biological activities like anti–inflammatory, anti–rheumatic, antihypertensive, andantipathogenic roles. In search of greener protocols,metal–free catalysts, and environmentally benign reaction conditions, a lot have been unboxed to date, and many other dimensions remain yet to be deciphered. This minireview is an attempt to classify various sustainable protocols for the synthesis of 1,4–benzothiazine scaffolds over the last decade based on the reacting components and pathways, along with the consideration of plausible mechanistic insights and critical analysis.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44568509","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}
B. Sahoo, B. Banik, A. Tiwari, V. Tiwari, Manojkumar Mahapatra
{"title":"Greener Approaches for Synthesis of Bioactive Thiadiazole Scaffolds","authors":"B. Sahoo, B. Banik, A. Tiwari, V. Tiwari, Manojkumar Mahapatra","doi":"10.2174/2213337210666230210142303","DOIUrl":"https://doi.org/10.2174/2213337210666230210142303","url":null,"abstract":"\u0000\u0000Thiadiazole is a paradigm of five membered heterocyclic compound that contains two nitrogens and one sulphur as heteroatoms with molecular formula C2H2N2S. Thiadiazole is mainly present in four isomeric forms such as 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole and 1,3,4-thiadiazole. Out of these isomers, 1,3,4-thiadiazole has attracted remarkable attention in the field of medicinal chemistry. Some of the drugs containing 1,3,4-thiadiazole moiety are used clinically and are available in the market including Sulphamethizole (Antibacterial), Acetazolamide (Diuretic), Azetepa (Antineoplastic), Cefazolin (Antibiotic), Megazol (Antiprotozoal), Atibeprone (anti-depressant). Several greener approaches are applied for the synthesis of thiadiazole scaffolds including microwave irradiation, ultrasonic irradiation, grinding, ball milling technique, etc. These methods are eco-friendly, nonhazardous, reproducible, and economical approach. Based on these Green chemistry approaches, thiadiazole derivatives are synthesized from thiosemicarbazide. The functionalization of these heterocyclic compounds generates thiadiazole derivatives with diverse chemical structures. This review covers green synthesis, biological potentials, and structure activity relationship study of thiadiazole analogs.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42496323","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 Simple and Modified One Pot Conversion of Carboxylic Acid to Ketone","authors":"Samaresh Jana, Debasis Sahoo, S. Sahoo","doi":"10.2174/2213337210666221223145319","DOIUrl":"https://doi.org/10.2174/2213337210666221223145319","url":null,"abstract":"\u0000\u0000Ketone is one of the important functional groups in synthetic chemistry. For this reason, organic chemists focused on the synthesis of ketone starting from various functionalities since nineties. One of the method deals with the conversion of carboxylic acids to ketones in a one pot manner. We have recently reported a one pot transformation of carboxylic acid to ketone using TsCl or MsCl as an activator of carboxylc acid. In our previous reports, two equivalents of organometallic reagent have been used which may not be useful in medicinal chemistry. In this report, we have developed an alternative process for the transformation where only one equivalent of organometallic reagent has been employed.\u0000\u0000\u0000\u0000In present scenario, we are interested to develop a process for the transformation of carboxylic acid to ketone using one equivalent of an organometallic reagent.\u0000\u0000\u0000\u0000A carboxylic acid reacted with tosyl chloride in the presence of a sodium hydride to form a mixed anhydride. Here, the acidic proton was removed from the reaction mixture as hydrogen gas. This mixed anhydride was then treated with one equivalent of an organomagnesium reagent at ̶̵ 30 °C to obtain the desired ketone.\u0000\u0000\u0000\u0000Following the optimum conditions, a few commercially available carboxylic acids were treated with TsCl, followed by the treatment of phenyl magnesium and methyl magnesium bromide to obtain phenyl and methyl ketones, respectively, in good to excellent yields.\u0000\u0000\u0000\u0000A simple and modified one pot method for the conversion of carboxylic acids to ketone has been reported. In this developed process, one equivalent of the organomagnesium reagent has been used to obtain the desired ketone under the optimized reaction conditions.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43710465","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, [Bmim]PF6-Catalyzed Synthesis of Benzoxazoles under Solvent-free Conditions","authors":"D. Duc","doi":"10.2174/2213337210666221214121957","DOIUrl":"https://doi.org/10.2174/2213337210666221214121957","url":null,"abstract":"\u0000\u0000An efficient and green strategy for the synthesis of 2-arylbenzoxazoles catalyzed by [Bmim]PF6 ionic liquid has been investigated via the condensation of o-aminophenol with aldehydes. The microwave-assisted synthesis features some advantages such as good yield of products, broad substrate scope, simple product purification, and absence of metal catalyst and solvent. Furthermore, the synthesis could be conveniently expanded to a gram scale.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43337488","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":"Recent Progress in Palladium Catalysed Sustainable Synthesis of Heterocycles","authors":"D. Saha, C. Mukhopadhyay","doi":"10.2174/2213337210666221208142224","DOIUrl":"https://doi.org/10.2174/2213337210666221208142224","url":null,"abstract":"\u0000\u0000Palladium metal has been extensively used in the synthesis of organic molecules for the last few decades. Heterocyclic ring synthesis being a significant part of organic synthesis, transition metal catalysis, especially catalysis by palladium, has been actively employed in heterocyclic synthesis. However, since palladium is an expensive metal, there has always been an urge to reuse or recycle the palladium catalyst to make the process economically viable. Modern synthetic chemists are also in constant search for newer sustainable strategies for molecular synthesis, which will lead to eco-friendly synthetic protocols. Thus, in the last few years, palladium catalysed green synthesis of heterocycles has gained importance as these aim to make the synthetic organic chemical world slightly more sustainable.\u0000\u0000\u0000\u0000This review comprises palladium catalysed synthetic strategies that proceed in a sustainable fashion. A few protocols included here involve either organic solvent-free or greener solvents as reaction medium, which is one of the modes adopted towards sustainability. Other modes of sustainability included in this review are recyclability of the palladium catalyst, one pot tandem reaction strategy, use of air as oxidant, etc. All these modes aim at achieving one or the other green chemistry principles like reduction of waste and by-products, increasing atom economy, reduction of cost and use of safer solvents.\u0000\u0000\u0000\u0000The review aims to reflect the scope of sustainability in palladium catalysed synthesis of heterocycles so that economically and environmentally viable synthetic methodologies may be selectively identified and applied in academia and industries.\u0000\u0000\u0000\u0000Keeping the principles of green chemistry in mind, in this review, we aim to compile the recent advancements in palladium catalysed sustainable synthesis of heterocycles in a single platter that may serve as a piece of reliable literature for further research in this area.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44297946","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}