Pub Date : 2023-03-22DOI: 10.2174/2211544712666230322092202
Ananda S Amarasekara, Bernard Wiredu, Moriam A. Animashaun
Processing of cellulose can be used to produce value added renewable feedstock chemicals. Catalytic depolymerization and processing of cellulose can be used to produce value added renewable feedstock chemicals. Development of an acidic ionic liquid - metal ion chloride catalyst system based single-reactor method for processing cellulose to value added products. The effect of metal chlorides as co-catalysts on 1-(1-propylsulfonic)-3-methylimidazolium chloride acidic ionic liquid catalyzed degradation of cellulose in 40 % (v/v) aq. ethanol was studied by measuring levulinic acid, ethyl levulinate and 5-hydroxymethylfurfural yields. In experiments with Mn(II), Zn(II) chloride co-catalysts at 160 and 170 °C for 12 h, the initial yields of ethyl levulinate and 5-hydroxymethylfurfural improved from ~ 7 % to ~ 12-15% due to co-catalytic effects. The highest enhancements in ethyl levulinate yields were observed with CrCl3, where the yield increased from 6 to 27 % with the addition of 10 mol% co-catalyst. All three transition metal chlorides studied produced improvements in yields of secondary products, ethyl levulinate and 5-hydroxymethylfurfural in acidic ionic liquid catalyzed degradation of cellulose in aqueous ethanol. The most significant enhancements in ethyl levulinate yields were observed with CrCl3 as a co-catalyst. none
{"title":"The Co-catalyst Effects of Mn(II), Zn(II), and Cr(III) Chlorides on Acidic Ionic Liquid Catalyzed Synthesis of Value-added Products from Cellulose in Aqueous Ethanol","authors":"Ananda S Amarasekara, Bernard Wiredu, Moriam A. Animashaun","doi":"10.2174/2211544712666230322092202","DOIUrl":"https://doi.org/10.2174/2211544712666230322092202","url":null,"abstract":"Processing of cellulose can be used to produce value added renewable feedstock chemicals. Catalytic depolymerization and processing of cellulose can be used to produce value added renewable feedstock chemicals. Development of an acidic ionic liquid - metal ion chloride catalyst system based single-reactor method for processing cellulose to value added products. The effect of metal chlorides as co-catalysts on 1-(1-propylsulfonic)-3-methylimidazolium chloride acidic ionic liquid catalyzed degradation of cellulose in 40 % (v/v) aq. ethanol was studied by measuring levulinic acid, ethyl levulinate and 5-hydroxymethylfurfural yields. In experiments with Mn(II), Zn(II) chloride co-catalysts at 160 and 170 °C for 12 h, the initial yields of ethyl levulinate and 5-hydroxymethylfurfural improved from ~ 7 % to ~ 12-15% due to co-catalytic effects. The highest enhancements in ethyl levulinate yields were observed with CrCl3, where the yield increased from 6 to 27 % with the addition of 10 mol% co-catalyst. All three transition metal chlorides studied produced improvements in yields of secondary products, ethyl levulinate and 5-hydroxymethylfurfural in acidic ionic liquid catalyzed degradation of cellulose in aqueous ethanol. The most significant enhancements in ethyl levulinate yields were observed with CrCl3 as a co-catalyst. none","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"228 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77555346","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 : 2023-01-10DOI: 10.2174/2211544712666230110152506
Ujjwal Pal, D. Chatterjee, Sagar Varangane
Photocatalytic transformation of small substrate molecules to useful products through an environmentally benign and economically viable pathway is a challenging area of research of continual importance. This review focuses on our perception of the application of ruthenium(III) complexes comprising ‘edta’ ligand (edta4- = ethylenediaminetetraacetate) as a ‘redox mediator’ or ‘relay’ in photocatalytic electron transfer reaction pertaining to the conversion of small substrate molecules viz. hydrazine to ammonia, bicarbonate to formate, dioxygen to hydrogen peroxide. In this article, the prospect of [RuIII(edta)(H2O)]- and [RuIII(edta)(pz)]- to act as ‘redox mediator’ or ‘molecular catalysts’ in photocatalytic transformations of aforesaid small molecules are assessed systematically.
{"title":"Application of Photo-inactive Ru(edta) complexes in Photocatalytic Small Molecules Transformation over Semiconductor Surface – A Perspective","authors":"Ujjwal Pal, D. Chatterjee, Sagar Varangane","doi":"10.2174/2211544712666230110152506","DOIUrl":"https://doi.org/10.2174/2211544712666230110152506","url":null,"abstract":"\u0000\u0000Photocatalytic transformation of small substrate molecules to useful products through an environmentally benign and economically viable pathway is a challenging area of research of continual importance. This review focuses on our perception of the application of ruthenium(III) complexes comprising ‘edta’ ligand (edta4- = ethylenediaminetetraacetate) as a ‘redox mediator’ or ‘relay’ in photocatalytic electron transfer reaction pertaining to the conversion of small substrate molecules viz. hydrazine to ammonia, bicarbonate to formate, dioxygen to hydrogen peroxide. In this article, the prospect of [RuIII(edta)(H2O)]- and [RuIII(edta)(pz)]- to act as ‘redox mediator’ or ‘molecular catalysts’ in photocatalytic transformations of aforesaid small molecules are assessed systematically.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91081969","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 : 2023-01-04DOI: 10.2174/2211544712666230104142809
Sushmita M. Roy
Pyridine is one of the most ubiquitous hetero-aromatic moieties in pharmaceutical chemistry and it has enormous importance in a plethora of fields. From a synthetic chemistry standpoint, pyridine moiety has been used as a directing group in C-H activation strategies to functionalize various rings. However, this unique feature to participate as a directing group hinders developing methodologies to carry out C-H activation on the pyridine ring itself. One of the simplest solutions is to block the activity of ring nitrogen at the cost of two extra steps. Here, in this review, along with the blocking, we will briefly mention some interesting ways to get around this problem and the remaining challenges ahead. The coordinating ability of pyridine N poses a big challenge toward C-H functionalization on the pyridine ring. This review summarizes some of the recent methods towards this challenge. Some key ideas towards that goal have been described. Here, the C-H activation strategies are categorised as follows: (1) Pyridine N-oxide mediated C-H activation, (2) Dimerization of C-H activation of pyridine, (3) Direct Pyridine C2-H activation, (4) Direct Pyridine C3-H activation and (5) Direct Pyridine C4-H activation. Several methods have been highlighted that can be utilised to prepare C-H functionalized products with regiospecificity that subsequently may be manipulated into interesting products which are difficult to attain easily. This review explores various new direct C-H activation methods on pyridine which attempts to fill the void of traditional synthetic protocols in regard to regioselective pyridine functionalization. This review also explores the limitations of current methodologies which must be wiped off to attain a mature state in need of the pharmaceutical industry.
{"title":"Recent Advances in Direct Pyridine C-H Activation Strategies","authors":"Sushmita M. Roy","doi":"10.2174/2211544712666230104142809","DOIUrl":"https://doi.org/10.2174/2211544712666230104142809","url":null,"abstract":"\u0000\u0000Pyridine is one of the most ubiquitous hetero-aromatic moieties in pharmaceutical chemistry and it has enormous importance in a plethora of fields. From a synthetic chemistry standpoint, pyridine moiety has been used as a directing group in C-H activation strategies to functionalize various rings. However, this unique feature to participate as a directing group hinders developing methodologies to carry out C-H activation on the pyridine ring itself. One of the simplest solutions is to block the activity of ring nitrogen at the cost of two extra steps. Here, in this review, along with the blocking, we will briefly mention some interesting ways to get around this problem and the remaining challenges ahead.\u0000\u0000\u0000\u0000The coordinating ability of pyridine N poses a big challenge toward C-H functionalization on the pyridine ring. This review summarizes some of the recent methods towards this challenge.\u0000\u0000\u0000\u0000Some key ideas towards that goal have been described. Here, the C-H activation strategies are categorised as follows: (1) Pyridine N-oxide mediated C-H activation, (2) Dimerization of C-H activation of pyridine, (3) Direct Pyridine C2-H activation, (4) Direct Pyridine C3-H activation and (5) Direct Pyridine C4-H activation.\u0000\u0000\u0000\u0000Several methods have been highlighted that can be utilised to prepare C-H functionalized products with regiospecificity that subsequently may be manipulated into interesting products which are difficult to attain easily.\u0000\u0000\u0000\u0000This review explores various new direct C-H activation methods on pyridine which attempts to fill the void of traditional synthetic protocols in regard to regioselective pyridine functionalization. This review also explores the limitations of current methodologies which must be wiped off to attain a mature state in need of the pharmaceutical industry.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89536784","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 : 2023-01-03DOI: 10.2174/2211544712666230103163911
S. D. Kurbah
An eco-friendly catalyst was synthesized in good yield and characterized by various physicochemical techniques. The catalytic performance of the environmentally benign complex was investigated via slurry synthesis of oximes. The catalytic studies were successfully carried out using a simple protocol. The fascinating advantage of this protocol is cost effectiveness, simple work up, good yield, short reactions time, and milder reaction conditions. The complex was prepared by reaction of vanadium pentoxide with hydrazone ligand in 1:1 molar ratios, and to this reaction mixture, potassium carbonate (0.14 g, 1 mmol) was added and ground till fine yellow colour powder appeared. Oximations were carried out by reacting the substrates, 15 % H2O2, ammonia and vanadium(V) complex. The reaction was taken in a mortar and ground till a fine powder appeared. After completion of the reaction, the crude product was extracted using dichloromethane/water in 1:2, v/v, evaporated and dried under vacuum. We synthesized different varieties of oximes using our newly synthesized complex as a catalyst. The products were characterized by 1H NMR and 13C NMR spectroscopy. The completion of the reaction was monitored by checking the complete disappearance of the aldehyde proton and the appearance of oxime protons. We also grew some single crystals of the products to provide further supporting evidences about the formation of products. Oximation of various carbonyl compounds was prepared quantitatively under the slurry condition, using {[K(H¬2O)3][V(O)2L]}2 as a catalyst. The catalytic reactions can be carried out under mild conditions, with ease of scalability, and straightforward work-up procedure, which makes the present protocols greener and better alternative methods for the synthesis of oximes.
{"title":"One Pot Synthesis of Oximes from Carbonyl Compounds Catalysed by Vanadium(V) Complex","authors":"S. D. Kurbah","doi":"10.2174/2211544712666230103163911","DOIUrl":"https://doi.org/10.2174/2211544712666230103163911","url":null,"abstract":"\u0000\u0000An eco-friendly catalyst was synthesized in good yield and characterized by various physicochemical techniques. The catalytic performance of the environmentally benign complex was investigated via slurry synthesis of oximes. The catalytic studies were successfully carried out using a simple protocol. The fascinating advantage of this protocol is cost effectiveness, simple work up, good yield, short reactions time, and milder reaction conditions.\u0000\u0000\u0000\u0000The complex was prepared by reaction of vanadium pentoxide with hydrazone ligand in 1:1 molar ratios, and to this reaction mixture, potassium carbonate (0.14 g, 1 mmol) was added and ground till fine yellow colour powder appeared. Oximations were carried out by reacting the substrates, 15 % H2O2, ammonia and vanadium(V) complex. The reaction was taken in a mortar and ground till a fine powder appeared. After completion of the reaction, the crude product was extracted using dichloromethane/water in 1:2, v/v, evaporated and dried under vacuum.\u0000\u0000\u0000\u0000We synthesized different varieties of oximes using our newly synthesized complex as a catalyst. The products were characterized by 1H NMR and 13C NMR spectroscopy. The completion of the reaction was monitored by checking the complete disappearance of the aldehyde proton and the appearance of oxime protons. We also grew some single crystals of the products to provide further supporting evidences about the formation of products.\u0000\u0000\u0000\u0000Oximation of various carbonyl compounds was prepared quantitatively under the slurry condition, using {[K(H¬2O)3][V(O)2L]}2 as a catalyst. The catalytic reactions can be carried out under mild conditions, with ease of scalability, and straightforward work-up procedure, which makes the present protocols greener and better alternative methods for the synthesis of oximes.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"173 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79543015","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 : 2022-08-01DOI: 10.2174/2211544712666221125141621
N. Das, Priyamabada Mahapatra
As a major source of pollutant, the effluents of dye based industries are mostly associated with several toxic heavy metals. Limited efforts have been made on simultaneous removal of both dyes and heavy metals from these effluents through adsorption/photocatalysis processes. Spinel ferrites with narrow band gap and high stability are suitable for further exploitation in this regard. Synthesis and characterisation of manganese ferrite nanoparticle and to assess its efficiency towards removal of organic dyes and hexavalent chromium in single and binary component systems are the objectives of this study. Manganese ferrite nanoparticle (MF NPs), prepared by coprecipitation, was characterised systematically by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Visible diffuse reflectance and magnetic measurement. Adsorptive and photocatalytic performances of the material under visible light were evaluated using aqueous solutions of different dyes and Cr(VI). Characterisation by various techniques revealed the formation of cubic MF nanoparticles with narrow band gap (1.78 eV) and moderate saturation magnetization (38.5 emu/g). In comparison, the anionic dyes and Cr(VI) were better adsorbed on MF, while photoactivity was more pronounced in the case of cationic dye. MF NPs displayed potential for photo-degradation/reduction of different dyes and Cr(VI) individually or simultaneously under visible light. The catalyst can be recovered magnetically from the reaction mixture for recycling and further use.
{"title":"Simultaneous Adsorptive/photocatalytic Removal of Organic Dyes and\u0000Hexavalent Chromium in Single and Binary Component Systems by Manganese\u0000Ferrite Nanoparticles","authors":"N. Das, Priyamabada Mahapatra","doi":"10.2174/2211544712666221125141621","DOIUrl":"https://doi.org/10.2174/2211544712666221125141621","url":null,"abstract":"\u0000\u0000As a major source of pollutant, the effluents of dye based industries are mostly associated with several toxic heavy metals. Limited efforts have been made on simultaneous removal of both dyes and heavy metals from these effluents through adsorption/photocatalysis processes. Spinel ferrites with narrow band gap and high stability are suitable for further exploitation in this regard.\u0000\u0000\u0000\u0000Synthesis and characterisation of manganese ferrite nanoparticle and to assess its efficiency towards removal of organic dyes and hexavalent chromium in single and binary component systems are the objectives of this study.\u0000\u0000\u0000\u0000Manganese ferrite nanoparticle (MF NPs), prepared by coprecipitation, was characterised systematically by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Visible diffuse reflectance and magnetic measurement. Adsorptive and photocatalytic performances of the material under visible light were evaluated using aqueous solutions of different dyes and Cr(VI).\u0000\u0000\u0000\u0000Characterisation by various techniques revealed the formation of cubic MF nanoparticles with narrow band gap (1.78 eV) and moderate saturation magnetization (38.5 emu/g). In comparison, the anionic dyes and Cr(VI) were better adsorbed on MF, while photoactivity was more pronounced in the case of cationic dye.\u0000\u0000\u0000\u0000MF NPs displayed potential for photo-degradation/reduction of different dyes and Cr(VI) individually or simultaneously under visible light. The catalyst can be recovered magnetically from the reaction mixture for recycling and further use.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87096159","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}