Pub Date : 2021-07-05DOI: 10.1515/9783110590050-006
E. Massolo, M. Benaglia
{"title":"6 Stereoselective organocascades: from fundamentals to recent developments","authors":"E. Massolo, M. Benaglia","doi":"10.1515/9783110590050-006","DOIUrl":"https://doi.org/10.1515/9783110590050-006","url":null,"abstract":"","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":"26 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91228834","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 : 2021-06-09DOI: 10.2174/2213337208666210609124432
M. Mir, M. Ashraf, A. Hussain, B. Mir
Soil is an ultimate source of all types of nutrients, which have both biological and non-biological importance. Studies are being carried out to isolate various types of micro-organisms from soil which have much more importance. So in the present study, amylase producing bacteria have been isolated from various soil samples. The isolation, identification, and estimation of various microbial strains for α-amylase enzyme production and then the inhibition of the growth of these microbial stains. The bacterial strains were isolated and then identified by various microbiological methods, including Gram’s staining method followed by several biochemical methods such as, litmus test, Gelatin test and Urea agar media and by viable cells. Altogether, three microbial strains were identified from the soil samples in the concerned study. The concerned strains include- Shigella, Proteus and Bacillus, respectively. The concerned microbial strains were then analyzed for the amount of amylase enzyme and it had been found that Bacillus sp produces much more amount of amylase followed by Shigella sp, and lesser amylase enzyme producing activity was found in Proteus sp. The isolated bacteria were then analysed for inhibition of their growth by water and ethanolic extracts of Cuminum cyminuni. Among the extracts, it had been found that water extracts exhibited more inhibiting capacity than the ethanolic extracts. The study also revealed that among the bacterial strains, the Shigella sp got much more affected by the concerned plant extracts followed by Proteus sp and least inhibition was observed against the Bacillus sp. As per the above study, it is being concluded that - three amylase producing bacteria viz Shigella, proteus, bacillus sp were isolated from the soil samples. These isolated microbial strains could be used for the decomposition of cholesterol levels in human in addition to other microbial activity. These isolated bacterial could sometimes be averse therefore their growth could be stopped by various biological and chemical substances like Gentamicin and by various Plant extracts viz, Cuminum cyminuni Plant.
{"title":"Isolation, Detection and Estimation of Various Amylase Producing Bacteria in Various Soil Samples","authors":"M. Mir, M. Ashraf, A. Hussain, B. Mir","doi":"10.2174/2213337208666210609124432","DOIUrl":"https://doi.org/10.2174/2213337208666210609124432","url":null,"abstract":"\u0000\u0000Soil is an ultimate source of all types of nutrients, which have both biological and non-biological importance. Studies are being carried out to isolate various types of micro-organisms from soil which have much more importance. So in the present study, amylase producing bacteria have been isolated from various soil samples. \u0000\u0000\u0000\u0000The isolation, identification, and estimation of various microbial strains for α-amylase enzyme production and then the inhibition of the growth of these microbial stains. \u0000\u0000\u0000\u0000The bacterial strains were isolated and then identified by various microbiological methods, including Gram’s staining method followed by several biochemical methods such as, litmus test, Gelatin test and Urea agar media and by viable cells. \u0000\u0000\u0000\u0000Altogether, three microbial strains were identified from the soil samples in the concerned study. The concerned strains include- Shigella, Proteus and Bacillus, respectively. The concerned microbial strains were then analyzed for the amount of amylase enzyme and it had been found that Bacillus sp produces much more amount of amylase followed by Shigella sp, and lesser amylase enzyme producing activity was found in Proteus sp. The isolated bacteria were then analysed for inhibition of their growth by water and ethanolic extracts of Cuminum cyminuni. Among the extracts, it had been found that water extracts exhibited more inhibiting capacity than the ethanolic extracts. The study also revealed that among the bacterial strains, the Shigella sp got much more affected by the concerned plant extracts followed by Proteus sp and least inhibition was observed against the Bacillus sp. \u0000\u0000\u0000\u0000As per the above study, it is being concluded that - three amylase producing bacteria viz Shigella, proteus, bacillus sp were isolated from the soil samples. These isolated microbial strains could be used for the decomposition of cholesterol levels in human in addition to other microbial activity. These isolated bacterial could sometimes be averse therefore their growth could be stopped by various biological and chemical substances like Gentamicin and by various Plant extracts viz, Cuminum cyminuni Plant.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45061813","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 : 2021-04-01DOI: 10.2174/22133372mta4emtia1
Gurpreet Kaur
{"title":"Mandelic Acid: An Efficient Organo-catalyst for the Synthesis of 3-substituted-3- Hydroxy-indolin-2-ones and Related Derivatives in Aqueous Ethanol at Room Temperature","authors":"Gurpreet Kaur","doi":"10.2174/22133372mta4emtia1","DOIUrl":"https://doi.org/10.2174/22133372mta4emtia1","url":null,"abstract":"","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68186936","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 : 2021-03-21DOI: 10.2174/2213337207999201029234021
Rajib Sarkar, C. Mukhopadhyay
The use of small organic molecules as organocatalysts in organic synthesis has been intensely studied over the past decade. In this emerging field, considerable studies have led to the introduction of various efficient organocatalyzed synthetic methods of carbon-carbon and carbon- heteroatom bond formations. The use of these organocatalysts also showed environmentally benign reaction conditions compared to the metal-catalyzed transformations. In this review, we paid special attention to the most recent organocatalytic protocols reported for the synthesis of heterocycles. The studies have been outlined, depending on the organocatalysts used as: (i) nitrogen-based molecules as organocatalyst, (ii) NHCs as organocatalyst, and (iii) phosphorus-based molecules as organocatalysts. The discussion intends to reveal the scope as well as the vitality of organocatalysis in the area of heterocycle synthesis.
{"title":"Organocatalytic Synthesis of Heterocycles: A Brief Overview Covering Recent Aspects","authors":"Rajib Sarkar, C. Mukhopadhyay","doi":"10.2174/2213337207999201029234021","DOIUrl":"https://doi.org/10.2174/2213337207999201029234021","url":null,"abstract":"\u0000\u0000The use of small organic molecules as organocatalysts in organic synthesis has been intensely\u0000studied over the past decade. In this emerging field, considerable studies have led to the introduction\u0000of various efficient organocatalyzed synthetic methods of carbon-carbon and carbon-\u0000heteroatom bond formations. The use of these organocatalysts also showed environmentally benign\u0000reaction conditions compared to the metal-catalyzed transformations. In this review, we paid\u0000special attention to the most recent organocatalytic protocols reported for the synthesis of heterocycles.\u0000The studies have been outlined, depending on the organocatalysts used as: (i) nitrogen-based\u0000molecules as organocatalyst, (ii) NHCs as organocatalyst, and (iii) phosphorus-based molecules as\u0000organocatalysts. The discussion intends to reveal the scope as well as the vitality of organocatalysis\u0000in the area of heterocycle synthesis.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48828574","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 : 2021-01-12DOI: 10.2174/2213337208666210112162443
W. Hassan, Mehreen Zafar, J. Kamdem, A. Duarte, J. D. da Rocha, M. Kamal
The sole objective of the present study is to explore the research trends in photocatalysis. In this area, the first document was published in the year 1921 and untill August 2020, a total of 6940 documents are archived in Scopus database. Its worthy to note that after 2000 a remarkable increase in publications has been noticed. Infact 6605 articles are published after 2000. The highest number of publications are reported in 2019 (784/11.87% of 6605) followed by 2018 (740/11.20% of 6605) and 2017 (624/9.45% of 6605). We calculated the per year growth rate and doubling time of publications. In research publications, the top three (3) countries are China (3030/43.65%), USA (704/10.14%) and India (503/7.24%). We provided the details which may explain, why China is the global leader in photocatalysis research. Furthermore, by Vosviewer analysis we provided the co-authorship and citations details of only research articles and reviews (total 6197 documents). Based on the (a) number of publications and (b) citations, the list of top ten (10) authors, institutes, countries and sources details are provided. We also performed the Vosviewer analysis for China’s publications (n=3030)The details about the top authors, institutes and collaborative countries are provided. One of the fundamental question is; what has been covered in photocatalysis research articles and reviews (n=6197)? For the purpose, we manually analyzed 47,722 keywords and grouped them in different categories. Mostly the document covered research under the names of photocatalysis, semiconductors, photochemical sources, instrumental techniques, electrochemistry, nanomaterials and water treatment. We extended the idea and explored the research publications in selected semiconductors (like titanium, graphene, cadmium, bismuth and iron based compounds), water purification, toxic pollutants, photcatalytic reduction of carbon dioxide, nanomaterials and certain specific instruments like SEM, TEM & XRD etc.
{"title":"Trends in Photocatalysis Research From Year 2000 to 2020","authors":"W. Hassan, Mehreen Zafar, J. Kamdem, A. Duarte, J. D. da Rocha, M. Kamal","doi":"10.2174/2213337208666210112162443","DOIUrl":"https://doi.org/10.2174/2213337208666210112162443","url":null,"abstract":"\u0000\u0000The sole objective of the present study is to explore the research trends in photocatalysis.\u0000\u0000\u0000\u0000\u0000In this area, the first document was published in the year 1921 and untill August 2020, a total of\u00006940 documents are archived in Scopus database.\u0000\u0000\u0000\u0000Its worthy to note that after 2000 a remarkable increase in publications has been noticed. Infact\u00006605 articles are published after 2000. The highest number of publications are reported in 2019 (784/11.87% of 6605)\u0000followed by 2018 (740/11.20% of 6605) and 2017 (624/9.45% of 6605). We calculated the per year growth rate and doubling\u0000time of publications. In research publications, the top three (3) countries are China (3030/43.65%), USA (704/10.14%) and\u0000India (503/7.24%). We provided the details which may explain, why China is the global leader in photocatalysis research.\u0000Furthermore, by Vosviewer analysis we provided the co-authorship and citations details of only research articles and reviews\u0000(total 6197 documents). Based on the (a) number of publications and (b) citations, the list of top ten (10) authors, institutes,\u0000countries and sources details are provided. We also performed the Vosviewer analysis for China’s publications (n=3030)The\u0000details about the top authors, institutes and collaborative countries are provided. One of the fundamental question is; what\u0000has been covered in photocatalysis research articles and reviews (n=6197)? For the purpose, we manually analyzed 47,722\u0000keywords and grouped them in different categories.\u0000\u0000\u0000\u0000 Mostly the document covered research under the names of photocatalysis, semiconductors, photochemical\u0000sources, instrumental techniques, electrochemistry, nanomaterials and water treatment. We extended the idea and explored\u0000the research publications in selected semiconductors (like titanium, graphene, cadmium, bismuth and iron based compounds), water purification, toxic pollutants, photcatalytic reduction of carbon dioxide, nanomaterials and certain specific\u0000instruments like SEM, TEM & XRD etc.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44668326","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 : 2020-12-28DOI: 10.2174/2213337207999201228141906
Dhanaji V. Jawale, Devendra S. Wagare, D. Lingampalle, Prashant D. Netankar
1,4-benzothiazine carboxylates show wide application in the field of medicinal chemistry. Therefore, we have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Synthesis of 1,4-benzothiazine carboxylates and its guanidines by simple and facile method using efficient catalyst. Derivatives of 1,4-benzothiazine carboxylates were synthesized by cyclocondensing β-keto esters with 2- aminobenzenethiols using CAN as a catalyst at room temperature. 1,4-benzothiazine caboxylate,condensed with guanidine hydrochloride in the presence of sodium methoxide in DMF to obtained new 3-substituted-l-4Hbenzo[b][1,4]thiazine-2-carboxyguanidines (88-91%). All the products were obtained with good to excellent yields within 40 min. Here, CAN oxidizes aminothiophenol into disulfide and then nucleophilic attack of enolic form of β-ketoesters on the disulphide and 1, 4-benzothiazine acetates, were obtained with good yields. We have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Most remarkable features of this cyclocondensation such as use of efficient catalyst and non-volatile solvent under mild reaction condition to obtained excellent yield.
{"title":"Synthesis of 3-methyl-4H-benzo[b][1,4]thiazine-2-carboxylates using CAN as a catalyst and its conversion into guanidines.","authors":"Dhanaji V. Jawale, Devendra S. Wagare, D. Lingampalle, Prashant D. Netankar","doi":"10.2174/2213337207999201228141906","DOIUrl":"https://doi.org/10.2174/2213337207999201228141906","url":null,"abstract":"\u0000\u00001,4-benzothiazine carboxylates show wide application in the field of medicinal chemistry. Therefore, we have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates.\u0000\u0000\u0000\u0000Synthesis of 1,4-benzothiazine carboxylates and its guanidines by simple and facile method using efficient catalyst.\u0000\u0000\u0000\u0000Derivatives of 1,4-benzothiazine carboxylates were synthesized by cyclocondensing β-keto esters with 2-\u0000aminobenzenethiols using CAN as a catalyst at room temperature. 1,4-benzothiazine caboxylate,condensed with guanidine hydrochloride in the presence of sodium methoxide in DMF to obtained new 3-substituted-l-4Hbenzo[b][1,4]thiazine-2-carboxyguanidines (88-91%).\u0000\u0000\u0000\u0000All the products were obtained with good to excellent yields within 40 min. Here, CAN oxidizes aminothiophenol into disulfide and then nucleophilic attack of enolic form of β-ketoesters on the disulphide and 1, 4-benzothiazine acetates, were obtained with good yields.\u0000\u0000\u0000\u0000We have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Most\u0000remarkable features of this cyclocondensation such as use of efficient catalyst and non-volatile solvent under mild reaction\u0000condition to obtained excellent yield.\u0000\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44230878","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 : 2020-11-17DOI: 10.2174/2213337207999201117093848
Kantharaju Kamanna
This review highlights the application of biopolymers of natural α-amino acids and its derived wild-type peptides employed as organocatalysts for the asymmetric synthesis of various important compounds published by researchers across the globe. The α-amino acid with L-configuration is available commercially in the pure form and plays a crucial role in enantioselective chiral molecule synthesis. Out of twenty natural amino acids, only one secondary amine-containing proline amino acid exhibited revolution in the field of organocatalysis because of its rigid structure and the formation of an imine like transition state during the reaction, which leads to more stereoselectivity. Hence, it is referred to as a simple enzyme in organocatalyst. Chiral enantioselective organic molecule synthesis has been further discussed by employing oligopeptides derived from the natural amino acids as a robust biocatalyst that replaced enzyme catalysts. The di-, tri, tetra-, penta- and oligopeptide derived from the natural amino acids are demonstrated as a potential organocatalyst, whose catalytic activity and mechanistic pathways are reviewed in the present paper. Several choices of organocatalyst are developed to achieve a facile and efficient stereoselective synthesis of many complex natural products with optically pure isomer. Subsequently, the researcher developed green and sustainable heterogeneous catalytic system containing organocatalyst immobilized onto solid inorganic support or porous material for accelerating reaction rate with asymmetric one isomer product through the heterogeneous phase. Further, researchers developed heterogeneous organocatalysts-Metal-Organic Frameworks (MOFs) that emerged as alternative simple and facile heterogeneous catalysts for the bulk production and flow reactor for enantioselective synthesis. This review compiled many outstanding discoveries in organocatalysts derivative of amino acids, peptides and heterogenized-MOFs employed for many organic transformations in research and industrial applications.
{"title":"Amino Acids and Peptides Organocatalysts: A Brief Overview on Its Evolution and Applications in Organic Asymmetric Synthesis","authors":"Kantharaju Kamanna","doi":"10.2174/2213337207999201117093848","DOIUrl":"https://doi.org/10.2174/2213337207999201117093848","url":null,"abstract":"\u0000\u0000This review highlights the application of biopolymers of natural α-amino acids and its\u0000derived wild-type peptides employed as organocatalysts for the asymmetric synthesis of various important\u0000compounds published by researchers across the globe. The α-amino acid with L-configuration\u0000is available commercially in the pure form and plays a crucial role in enantioselective chiral\u0000molecule synthesis. Out of twenty natural amino acids, only one secondary amine-containing proline\u0000amino acid exhibited revolution in the field of organocatalysis because of its rigid structure\u0000and the formation of an imine like transition state during the reaction, which leads to more stereoselectivity.\u0000Hence, it is referred to as a simple enzyme in organocatalyst. Chiral enantioselective organic\u0000molecule synthesis has been further discussed by employing oligopeptides derived from the\u0000natural amino acids as a robust biocatalyst that replaced enzyme catalysts. The di-, tri, tetra-,\u0000penta- and oligopeptide derived from the natural amino acids are demonstrated as a potential\u0000organocatalyst, whose catalytic activity and mechanistic pathways are reviewed in the present paper.\u0000Several choices of organocatalyst are developed to achieve a facile and efficient stereoselective\u0000synthesis of many complex natural products with optically pure isomer. Subsequently, the researcher\u0000developed green and sustainable heterogeneous catalytic system containing organocatalyst\u0000immobilized onto solid inorganic support or porous material for accelerating reaction rate with\u0000asymmetric one isomer product through the heterogeneous phase. Further, researchers developed\u0000heterogeneous organocatalysts-Metal-Organic Frameworks (MOFs) that emerged as alternative\u0000simple and facile heterogeneous catalysts for the bulk production and flow reactor for enantioselective\u0000synthesis. This review compiled many outstanding discoveries in organocatalysts derivative of\u0000amino acids, peptides and heterogenized-MOFs employed for many organic transformations in research\u0000and industrial applications.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45125325","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 : 2020-08-05DOI: 10.2174/2213337207999200805115813
N. Demirbas, A. Demirbaş
Since the discovery of metal-free catalysts or organocatalysts about twenty years ago, a number of small molecules with different structures have been used to accelerate organic transformations. With the development of environmental awareness, to obtain highly efficient scaffolds, scientists have directed their studies towards synthetic methodologies that minimize or preferably eliminate the formation of waste, avoid toxic solvents and reagents and use renewable starting materials as far as possible. In this connection, the organocatalytic reactions providing efficiency and selectivity for most of the transformations have become an endless topic in organic chemistry since several advantages from both practical and environmental standpoints. Organocatalysts contributing to the transformation of reactants into products with the least possible waste production, have been serving the concept of green chemistry. Organocatalysts have been classified based on their binding capacity to the substrate with covalent or noncovalent interactions involving hydrogen bonding and electrostatic interaction. Diverse types of small organic compounds including proline and its derivatives, phase-transfer catalysts, (thio)urease, phosphoric acids, sulfones, N-oxides, guanidines, cinchona derivatives, aminoindanol, and amino acids have been utilized as hydrogen bonding organocatalysts in different chemical transformations.
{"title":"Organocatalyzed Heterocyclic Transformations In Green Media: A Review","authors":"N. Demirbas, A. Demirbaş","doi":"10.2174/2213337207999200805115813","DOIUrl":"https://doi.org/10.2174/2213337207999200805115813","url":null,"abstract":"\u0000\u0000Since the discovery of metal-free catalysts or organocatalysts about twenty\u0000years ago, a number of small molecules with different structures have been used to accelerate organic\u0000transformations. With the development of environmental awareness, to obtain highly efficient\u0000scaffolds, scientists have directed their studies towards synthetic methodologies that minimize\u0000or preferably eliminate the formation of waste, avoid toxic solvents and reagents and use renewable\u0000starting materials as far as possible.\u0000\u0000\u0000\u0000 In this connection, the organocatalytic reactions providing efficiency and selectivity for\u0000most of the transformations have become an endless topic in organic chemistry since several advantages\u0000from both practical and environmental standpoints. Organocatalysts contributing to the transformation\u0000of reactants into products with the least possible waste production, have been serving the\u0000concept of green chemistry.\u0000\u0000\u0000\u0000Organocatalysts have been classified based on their binding capacity to\u0000the substrate with covalent or noncovalent interactions involving hydrogen bonding and electrostatic\u0000interaction. Diverse types of small organic compounds including proline and its derivatives,\u0000phase-transfer catalysts, (thio)urease, phosphoric acids, sulfones, N-oxides, guanidines, cinchona\u0000derivatives, aminoindanol, and amino acids have been utilized as hydrogen bonding organocatalysts\u0000in different chemical transformations.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41345688","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 : 2020-07-13DOI: 10.2174/2213337207999200713145440
G. Kaur, Rajat Kumar, Shivam Saroch, V. Gupta, B. Banerjee
Indoles and various indolyl derivatives are very common in naturally occurring biologically active compounds. Many methods are being developed for the synthesis of various bioactive indole derivatives. Synthesis of biologically promising structurally diverse indole derivatives under mild and environmentally benign conditions. Synthesis of 3-hydroxy-3-(5-(trifluoromethoxy)-1H-indol-3-yl)indolin-2-one was achieved by the reaction of an equimolar mixture of isatin and 3-(trifluoromethoxy)-1H-indol using 20 mol% of mandelic acid as catalyst in aqueous ethanol at room temperature. Under the same optimized reaction conditions, synthesis of 3-(3-hydroxy-2-oxoindolin-3-yl)chroman-2,4-diones was accomplished via the reactions of substituted isatins and 4-hydroxycoumarin. On the other hand, 2-hydroxy-2-(indol-3-yl)- indene-1,3-diones and 10-hydroxy-10-(5-methoxy-1H-indol-3- yl)phenanthren-9(10H)-one were synthesized from the reactions of indoles and ninhydrin or 9,10-phenanthrenequinone respectively using the same 20 mol% of mandelic acid as an efficient organo-catalyst in aqueous ethanol at room temperature. Mild, safe and clean reaction profiles, energy efficiency, high atom-economy, use of naturally occurring non-toxic organo-catalyst, easy isolation procedure by avoiding column chromatographic purification and gram scale production are some the major advantages of this developed protocol. A simple, straightforward and eco-friendly protocol has been developed for the efficient synthesis of biologically promising novel 3-hydroxy-3-(5-(trifluoromethoxy)-1H-indol- 3-yl)indolin-2- one, 3-(3-hydroxy-2-oxoindolin-3-yl)chroman-2,4-diones, 2-hydroxy-2-(indol-3- yl)-indene-1,3-diones and 10-hydroxy-10-(5-methoxy-1H-indol-3-yl)phenanthren-9(10H)-one using a catalytic amount of mandelic acid in aqueous ethanol at room temperature.
{"title":"Mandelic Acid: An Efficient Organo-catalyst for the Synthesis of 3-substituted-3- Hydroxy-indolin-2-ones and Related Derivatives in Aqueous Ethanol at Room Temperature","authors":"G. Kaur, Rajat Kumar, Shivam Saroch, V. Gupta, B. Banerjee","doi":"10.2174/2213337207999200713145440","DOIUrl":"https://doi.org/10.2174/2213337207999200713145440","url":null,"abstract":"\u0000\u0000Indoles and various indolyl derivatives are very common in naturally occurring\u0000biologically active compounds. Many methods are being developed for the synthesis of various\u0000bioactive indole derivatives.\u0000\u0000\u0000\u0000Synthesis of biologically promising structurally diverse indole derivatives under mild and\u0000environmentally benign conditions.\u0000\u0000\u0000\u0000Synthesis of 3-hydroxy-3-(5-(trifluoromethoxy)-1H-indol-3-yl)indolin-2-one was achieved\u0000by the reaction of an equimolar mixture of isatin and 3-(trifluoromethoxy)-1H-indol using 20 mol% of\u0000mandelic acid as catalyst in aqueous ethanol at room temperature. Under the same optimized reaction\u0000conditions, synthesis of 3-(3-hydroxy-2-oxoindolin-3-yl)chroman-2,4-diones was accomplished via the\u0000reactions of substituted isatins and 4-hydroxycoumarin. On the other hand, 2-hydroxy-2-(indol-3-yl)-\u0000indene-1,3-diones and 10-hydroxy-10-(5-methoxy-1H-indol-3- yl)phenanthren-9(10H)-one were synthesized\u0000from the reactions of indoles and ninhydrin or 9,10-phenanthrenequinone respectively using\u0000the same 20 mol% of mandelic acid as an efficient organo-catalyst in aqueous ethanol at room temperature.\u0000\u0000\u0000\u0000Mild, safe and clean reaction profiles, energy efficiency, high atom-economy, use of naturally\u0000occurring non-toxic organo-catalyst, easy isolation procedure by avoiding column chromatographic\u0000purification and gram scale production are some the major advantages of this developed protocol.\u0000\u0000\u0000\u0000A simple, straightforward and eco-friendly protocol has been developed for the efficient\u0000synthesis of biologically promising novel 3-hydroxy-3-(5-(trifluoromethoxy)-1H-indol- 3-yl)indolin-2-\u0000one, 3-(3-hydroxy-2-oxoindolin-3-yl)chroman-2,4-diones, 2-hydroxy-2-(indol-3- yl)-indene-1,3-diones\u0000and 10-hydroxy-10-(5-methoxy-1H-indol-3-yl)phenanthren-9(10H)-one using a catalytic amount of\u0000mandelic acid in aqueous ethanol at room temperature.\u0000","PeriodicalId":10945,"journal":{"name":"Current Organocatalysis","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44784517","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}
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