Pub Date : 2021-09-03DOI: 10.2174/2211544710666210903115735
R. Salomi, S. Sylvia, M. Abukhaled, L. Rajendran
A mathematical model for the combustion of ethanol and ethyl acetate mixtures using Mn9Cu1 (mixture of manganese and copper with a weight ratio of 9:1) catalyst is discussed. The model’s kinetic mechanism is expressed in terms of nonlinear reaction-diffusion equations with common initial and boundary conditions in a finite planar, cylindrical, and spherical geometry. A Taylor series approach is used to derive general approximate analytical expressions of ethanol, acetaldehyde, and ethyl acetate molar concentrations inside the particle and reactor phase for various values of rate constants, diffusion, and kinetic parameters. The effect of shape factor for the planar, cylindrical, and spherical geometry of dispersed particles was examined for the first time. Activation energy and rate constant at the reference temperature of ethanol, acetaldehyde, and ethyl acetate are also obtained from the rate equations. A direct comparison with numerical simulations confirms the accuracy of the derived analytical results. A mathematical model for the combustion of ethanol and ethyl acetate mixtures using Mn9Cu1 (mixture of manganese and copper with a weight ratio of 9:1) catalyst is discussed. The model’s kinetic mechanism is expressed in terms of nonlinear reaction-diffusion equations with common initial and boundary conditions in a finite planar, cylindrical, and spherical geometry. Derive general approximate analytical expressions of ethanol, acetaldehyde, and ethyl acetate molar concentrations inside the particle and reactor phase for various parameter values. We employ the simple and reliable Taylor series method. semi-analytic expressions of the concentration and bulk concentration of ethanol, ethyl acetate, and acetaldehyde. Approximate analytical expressions of the concentrations of ethanol, acetaldehyde and ethyl acetate were derived for arbitrary catalyst particle (planar, cylindrical and spherical) by using a simple, reliable, and robust method. In addition, the concentration of the species in reactor phase was also reported. The effects of the kinetic parameters, which are influenced by adsorption equilibrium constant, effective diffusivity, activation energy, on concentration, were discussed.
{"title":"Kinetics of the Catalytic Combustion of Ethanol and Ethyl Acetate with Estimation of Activation Energy and Rate Constants: An Analytical Study","authors":"R. Salomi, S. Sylvia, M. Abukhaled, L. Rajendran","doi":"10.2174/2211544710666210903115735","DOIUrl":"https://doi.org/10.2174/2211544710666210903115735","url":null,"abstract":"\u0000\u0000A mathematical model for the combustion of ethanol and ethyl acetate mixtures using Mn9Cu1 (mixture of manganese and copper with a weight ratio of 9:1) catalyst is discussed. The model’s kinetic mechanism is expressed in terms of nonlinear reaction-diffusion equations with common initial and boundary conditions in a finite planar, cylindrical, and spherical geometry. A Taylor series approach is used to derive general approximate analytical expressions of ethanol, acetaldehyde, and ethyl acetate molar concentrations inside the particle and reactor phase for various values of rate constants, diffusion, and kinetic parameters. The effect of shape factor for the planar, cylindrical, and spherical geometry of dispersed particles was examined for the first time. Activation energy and rate constant at the reference temperature of ethanol, acetaldehyde, and ethyl acetate are also obtained from the rate equations. A direct comparison with numerical simulations confirms the accuracy of the derived analytical results.\u0000\u0000\u0000\u0000\u0000 A mathematical model for the combustion of ethanol and ethyl acetate mixtures using Mn9Cu1 (mixture of manganese and copper with a weight ratio of 9:1) catalyst is discussed. The model’s kinetic mechanism is expressed in terms of nonlinear reaction-diffusion equations with common initial and boundary conditions in a finite planar, cylindrical, and spherical geometry.\u0000\u0000\u0000\u0000\u0000 Derive general approximate analytical expressions of ethanol, acetaldehyde, and ethyl acetate molar concentrations inside the particle and reactor phase for various parameter values.\u0000\u0000\u0000\u0000\u0000We employ the simple and reliable Taylor series method.\u0000\u0000\u0000\u0000\u0000 semi-analytic expressions of the concentration and bulk concentration of ethanol, ethyl acetate, and acetaldehyde.\u0000\u0000\u0000\u0000\u0000Approximate analytical expressions of the concentrations of ethanol, acetaldehyde and ethyl acetate were derived for arbitrary catalyst particle (planar, cylindrical and spherical) by using a simple, reliable, and robust method. In addition, the concentration of the species in reactor phase was also reported. The effects of the kinetic parameters, which are influenced by adsorption equilibrium constant, effective diffusivity, activation energy, on concentration, were discussed.\u0000\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"115 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88263422","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}
Synthesis of chalcone by Claisen–Schmidt condensation using recyclable L- aspartic acid coupled imidazolium-based ionic liquid as a green synthetic approach has been developed. Present work offers significant advantages such as high yield, enhanced reaction speed even at room temperature, catalyst reusability, and the involvement of non-toxic reagents. Chalcones are a flavonoid family and have pharmacological and biological activities. It includes antibacterial, antifungal, immunosuppressive, and anti-nociceptive properties. Ionic liquid has emerged as a powerful tool for molecular organic solvents and wide liquid range, ease of recovery and reuse, and making them a greener alternative to volatile organic solvents. Thus, our objective was to employ them as dual catalyst and solvent systems to synthesize chalcone via CS condensation in the present work. In a typical experiment, benzaldehyde (10 mmol), acetophenone (10 mmol), and 2.5 mol% (L-AAIL) ionic liquid were mixed in a 50 mL round-bottom flask. The reaction was preceded quickly at room temperature with stirring, the resulting mixture became a biphasic system with the residue at the bottom and the upper phase containing some unreacted substrate separated from the catalyst by filtration and decantation. The catalyst was extracted with CH2Cl2 and split for the next cycle. Claisen–Schmidt condensation accomplished with reasonable to good yields, ranged from 78 to 95% at room temperature in the presence of the [L-AAIL], as compared to the traditional route at more than 100O C. [L-AAIL] are found a highly efficient and eco-friendly catalyst for synthesizing chalcone derivatives at room temperature. [L-AAIL] as a solvent and catalyst will exhibit real advantages by providing a ‘green’ process with the safer operation, Short reaction periods, mild reaction conditions, easier separation, and reusability of ionic liquid made this methodology valuable for synthetic organic chemists as well as industry.
{"title":"An Efficient Synthesis Of α, β Unsaturated Ketones Via Claisen–Schmidt Condensation Reaction Using Amino Acid Based Ionic Liquids","authors":"Ganesh Gopalsamy Selvaraj, Sakthinarayanan Jayaraman, Uthayanila Selvarasu, Bharathi Priya Velumani, K. Parasuraman","doi":"10.2174/2211544710666210716113451","DOIUrl":"https://doi.org/10.2174/2211544710666210716113451","url":null,"abstract":"\u0000\u0000Synthesis of chalcone by Claisen–Schmidt condensation using recyclable L- aspartic acid coupled imidazolium-based ionic liquid as a green synthetic approach has been developed. Present work offers significant advantages such as high yield, enhanced reaction speed even at room temperature, catalyst reusability, and the involvement of non-toxic reagents.\u0000\u0000\u0000\u0000Chalcones are a flavonoid family and have pharmacological and biological activities. It includes antibacterial, antifungal, immunosuppressive, and anti-nociceptive properties. \u0000\u0000\u0000\u0000Ionic liquid has emerged as a powerful tool for molecular organic solvents and wide liquid range, ease of recovery and reuse, and making them a greener alternative to volatile organic solvents. Thus, our objective was to employ them as dual catalyst and solvent systems to synthesize chalcone via CS condensation in the present work.\u0000\u0000\u0000\u0000In a typical experiment, benzaldehyde (10 mmol), acetophenone (10 mmol), and 2.5 mol% (L-AAIL) ionic liquid were mixed in a 50 mL round-bottom flask. The reaction was preceded quickly at room temperature with stirring, the resulting mixture became a biphasic system with the residue at the bottom and the upper phase containing some unreacted substrate separated from the catalyst by filtration and decantation. The catalyst was extracted with CH2Cl2 and split for the next cycle. \u0000\u0000\u0000\u0000Claisen–Schmidt condensation accomplished with reasonable to good yields, ranged from 78 to 95% at room temperature in the presence of the [L-AAIL], as compared to the traditional route at more than 100O C.\u0000\u0000\u0000\u0000 [L-AAIL] are found a highly efficient and eco-friendly catalyst for synthesizing chalcone derivatives at room temperature. [L-AAIL] as a solvent and catalyst will exhibit real advantages by providing a ‘green’ process with the safer operation, Short reaction periods, mild reaction conditions, easier separation, and reusability of ionic liquid made this methodology valuable for synthetic organic chemists as well as industry.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80992210","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 : 2021-07-16DOI: 10.2174/2211544710666210716120321
G. Pavale, M. Ramana, Poornima Acharya, S. Shaikh
Metal oxide and metal oxide nanoparticles are gaining significant importance due to their reusability and wide range of catalytic applications in many organic transformations. To report simple and efficient Fe3O4 catalyzed one-pot five-component reaction protocol to synthesize novel thiophene containing aminonaphthols under solvent-free conditions. To prepare the Fe3O4 nanoparticles by facile and simple co-precipitation method and surface characterization was done using FT-IR, XRD, BET, SEM, and TEM analysis technique. Aminonaphthol derivatives bearing thiophene moiety were synthesized using Fe3O4 nanoparticles under solvent-free conditions. The prepared nanoparticles are smaller in size (15nm) and can be easily detachable. It can be recycled and reused five times without any significant loss of catalytic activity with excellent yields in a short time. The existing protocol for synthesizing amino naphthol becomes feasible and attractive due to the reusability of the catalyst, excellent catalytic performance, and eco-friendly procedure. In conclusion, Fe3O4 nanoparticles provide a simple, efficient, and greener one-pot five-component synthetic approach to synthesize thiophene containing aminonaphthols. Excellent catalytic activity was perceived in a short reaction time without any co-catalyst or any other activator. Moreover, reusability of catalyst, high yields, and environmentally benign solvent-free condition are vital factors of this protocol.
{"title":"One-pot Synthesis of Novel Thiophene Containing Aminonaphthols using Fe3O4 Nanoparticles as a Recyclable Heterogeneous Catalyst","authors":"G. Pavale, M. Ramana, Poornima Acharya, S. Shaikh","doi":"10.2174/2211544710666210716120321","DOIUrl":"https://doi.org/10.2174/2211544710666210716120321","url":null,"abstract":"\u0000\u0000Metal oxide and metal oxide nanoparticles are gaining significant importance due to their reusability and wide range of catalytic applications in many organic transformations.\u0000\u0000\u0000\u0000To report simple and efficient Fe3O4 catalyzed one-pot five-component reaction protocol to synthesize novel thiophene containing aminonaphthols under solvent-free conditions.\u0000\u0000\u0000\u0000To prepare the Fe3O4 nanoparticles by facile and simple co-precipitation method and surface characterization was done using FT-IR, XRD, BET, SEM, and TEM analysis technique. Aminonaphthol derivatives bearing thiophene moiety were synthesized using Fe3O4 nanoparticles under solvent-free conditions.\u0000\u0000\u0000\u0000The prepared nanoparticles are smaller in size (15nm) and can be easily detachable. It can be recycled and reused five times without any significant loss of catalytic activity with excellent yields in a short time. The existing protocol for synthesizing amino naphthol becomes feasible and attractive due to the reusability of the catalyst, excellent catalytic performance, and eco-friendly procedure.\u0000\u0000\u0000\u0000In conclusion, Fe3O4 nanoparticles provide a simple, efficient, and greener one-pot five-component synthetic approach to synthesize thiophene containing aminonaphthols. Excellent catalytic activity was perceived in a short reaction time without any co-catalyst or any other activator. Moreover, reusability of catalyst, high yields, and environmentally benign solvent-free condition are vital factors of this protocol.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89518773","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 : 2021-06-08DOI: 10.2174/2211544710666210608150209
F. Zulkifli, A. M. Md Jani, H. Yazid
The current work aims to enhance the catalytic performance of gold nanopar-ticle–carbon nanotube (Au-CNT) composites towards the reduction of p-nitrophenol. The synthesis of Au-CNT has received extensive attention because of their high stability and catalytic efficiency, particularly as a heterogeneous catalyst in the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) However, most of the Au-CNT preparation processes reported in the literature are time-consuming or require expensive instrumentation. In the present work, Au-CNT catalysts were synthesized via a straightforward, low-cost deposition–precipitation (DP) method. The aim of the study was to evaluate the effect of pH and aging time on catalytic activity of Au-CNTs catalyst. The Au-CNT nanocomposite catalysts were synthesized using a simple deposition–precipitation method and characterized by Brunauer–Emmett–Teller analysis, fourier transform infrared spectroscopy, atomic absorption spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, and trans-mission electron microscopy. The particle size and the loading of Au nanoparticles on the CNTs can be easily controlled by varying the pH and aging time during the synthesis process. The nanocomposite catalysts exhibited excellent catalytic activity for the reduction of p-nitrophenol to p-aminophenol in the presence of excess sodium borohydride (NaBH4). The highest rate constant (k) achieved based on the pseudo-first-order kinetic model was 1.2 × 10-3 s-1. This study offers a simple and cost-effective route to synthesize Au-CNT catalysts with high stability and catalytic efficiency for large-scale applica-tions.
{"title":"Optimized Preparation of Gold Nanoparticles-loaded Carbon Nanotubes (Au-CNTs) as an Efficient Catalyst for p-Nitrophenol Reduction","authors":"F. Zulkifli, A. M. Md Jani, H. Yazid","doi":"10.2174/2211544710666210608150209","DOIUrl":"https://doi.org/10.2174/2211544710666210608150209","url":null,"abstract":"\u0000\u0000 The current work aims to enhance the catalytic performance of gold nanopar-ticle–carbon nanotube (Au-CNT) composites towards the reduction of p-nitrophenol.\u0000\u0000\u0000\u0000\u0000 The synthesis of Au-CNT has received extensive attention because of their high stability and catalytic efficiency, particularly as a heterogeneous catalyst in the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) However, most of the Au-CNT preparation processes reported in the literature are time-consuming or require expensive instrumentation. In the present work, Au-CNT catalysts were synthesized via a straightforward, low-cost deposition–precipitation (DP) method.\u0000\u0000\u0000\u0000\u0000 The aim of the study was to evaluate the effect of pH and aging time on catalytic activity of Au-CNTs catalyst.\u0000\u0000\u0000\u0000\u0000 The Au-CNT nanocomposite catalysts were synthesized using a simple deposition–precipitation method and characterized by Brunauer–Emmett–Teller analysis, fourier transform infrared spectroscopy, atomic absorption spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, and trans-mission electron microscopy.\u0000\u0000\u0000\u0000\u0000The particle size and the loading of Au nanoparticles on the CNTs can be easily controlled by varying the pH and aging time during the synthesis process. The nanocomposite catalysts exhibited excellent catalytic activity for the reduction of p-nitrophenol to p-aminophenol in the presence of excess sodium borohydride (NaBH4). The highest rate constant (k) achieved based on the pseudo-first-order kinetic model was 1.2 × 10-3 s-1.\u0000\u0000\u0000\u0000\u0000This study offers a simple and cost-effective route to synthesize Au-CNT catalysts with high stability and catalytic efficiency for large-scale applica-tions.\u0000\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88594540","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 : 2021-04-05DOI: 10.2174/2211544710666210405094331
G. Marandi, Salmeh Rasoulizadeh, M. Maghsoodlou
Chitin and pectin are important natural polymers which are used as natural catalyst for synthesis of tri- and tetra- phenyl substituted 1H-imidazoles. The reaction of benzil and aromatic aldehydes with ammonium acetate in the presence of chitin produces 2,4,5-triphenyl-1H-imidazoles and the reaction of benzil, aromatic aldehydes and aniline derivatives with ammonium acetate in the presence of pectin produces 1,2,4,5-tetraphenyl-1H-imidazoles, respectively. The results show that synthesis of 2,4,5-triphenyl-1H-imidazoles and 1,2,4,5-tetraphenyl-1H-imidazoles can be catalyzed by chitin and pectin in an effective route, respectively. All synthesized compounds are in good agreement with previously reported compounds. In conclusion, an efficient methodology has been carried out to generate 2,4,5-triphenyl-1H-imidazoles and 1,2,4,5-tetraphenyl-1H-imidazoles, by using non-toxic, cheap and in available catalysis (chitin and pectin).
甲壳素和果胶是重要的天然聚合物，是合成三苯基和四苯基取代1h -咪唑的天然催化剂。在甲壳素存在的情况下，苯并芳醛与乙酸铵反应生成2,4,5-三苯基- 1h -咪唑;在果胶存在的情况下，苯并芳醛和苯胺衍生物与乙酸铵反应生成1,2,4,5-四苯基- 1h -咪唑。结果表明，甲壳素和果胶分别可以有效地催化合成2,4,5-三苯基- 1h -咪唑和1,2,4,5-四苯基- 1h -咪唑。所有合成的化合物与先前报道的化合物一致。综上所述，本文提出了一种高效的合成2,4,5-三苯基-1 - h -咪唑和1,2,4,5-四苯基-1 - h -咪唑的方法，该方法使用无毒、廉价和可用的催化剂(几丁质和果胶)。
{"title":"Synthesis of tri- and tetra- phenyl substituted 1H-imidazoles in the presence of chitin and pectin as natural catalyst","authors":"G. Marandi, Salmeh Rasoulizadeh, M. Maghsoodlou","doi":"10.2174/2211544710666210405094331","DOIUrl":"https://doi.org/10.2174/2211544710666210405094331","url":null,"abstract":"\u0000\u0000Chitin and pectin are important natural polymers which are used as natural catalyst for synthesis of tri- and tetra- phenyl substituted 1H-imidazoles. \u0000\u0000\u0000\u0000The reaction of benzil and aromatic aldehydes with ammonium acetate in the presence of chitin produces 2,4,5-triphenyl-1H-imidazoles and the reaction of benzil, aromatic aldehydes and aniline derivatives with ammonium acetate in the presence of pectin produces 1,2,4,5-tetraphenyl-1H-imidazoles, respectively.\u0000\u0000\u0000\u0000The results show that synthesis of 2,4,5-triphenyl-1H-imidazoles and 1,2,4,5-tetraphenyl-1H-imidazoles can be catalyzed by chitin and pectin in an effective route, respectively. All synthesized compounds are in good agreement with previously reported compounds.\u0000\u0000\u0000\u0000In conclusion, an efficient methodology has been carried out to generate 2,4,5-triphenyl-1H-imidazoles and 1,2,4,5-tetraphenyl-1H-imidazoles, by using non-toxic, cheap and in available catalysis (chitin and pectin). \u0000\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"240 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76930525","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: 10.2174/2211544710666210401111704
E. B. Júnior, F. B. Neves, Samuel Q. Lopes, Fabrício H. Holanda, T. M. Souza, E. P. Pinto, Alex N. Oliveira, L. Fonseca, S. Yoshioka, I. Ferreira
Biodiesel has been shown to be effectively produced by immobilized enzymatic catalysts. The selection of support material is a prominent factor for obtaining an efficient lipase. Silk fibroin (SF) is a natural polymer, produced by glands of some arthropods, especially by the Bombyx mor, attracting attention for immobilization lipase attention. This paper presents a novel method to obtain silk microfibers (SMF) from Oxone® salt in water, used as support for Amano AK lipase from Pseudomonas fluorescens in biodiesel production from deodorization distillate of palm oil (DDPO). The oxone® salt in the presence of Ca2+ ions act as a mineralizing agent in the peptide bonds present in silk fibroin, altering some of its physical and chemical properties, such as zeta potential, crystallinity, micro-morphology, infrared spectroscopic profile, and showing formation or absence of SF original connections. The modified support was tested as a support alternative for the immobilization of Amano AK lipase from Pseudomonas fluorescens. Enzyme activity values indicated that lipase immobilization on SMF was efficient as a heterogeneous catalyst in the esterification of DDPO (deodorization distillate palm oil). The effect of some reaction parameters, such as catalyst concentration, molar ratio, temperature, and reaction time, was studied to optimize the conditions for maximum conversion of DDPO (40.5%).
{"title":"Immobilization of Amano AK lipase from Pseudomonas fluorescens on novel silk microfiber using Oxone®: Parameter optimization for enzymatic assays and use in esterification of residual palm oil","authors":"E. B. Júnior, F. B. Neves, Samuel Q. Lopes, Fabrício H. Holanda, T. M. Souza, E. P. Pinto, Alex N. Oliveira, L. Fonseca, S. Yoshioka, I. Ferreira","doi":"10.2174/2211544710666210401111704","DOIUrl":"https://doi.org/10.2174/2211544710666210401111704","url":null,"abstract":"\u0000\u0000Biodiesel has been shown to be effectively produced by immobilized enzymatic catalysts. The selection of support material is a prominent factor for obtaining an efficient lipase. Silk fibroin (SF) is a natural polymer, produced by glands of some arthropods, especially by the Bombyx mor, attracting attention for immobilization lipase attention.\u0000\u0000\u0000\u0000This paper presents a novel method to obtain silk microfibers (SMF) from Oxone® salt in water, used as support for Amano AK lipase from Pseudomonas fluorescens in biodiesel production from deodorization distillate of palm oil (DDPO). \u0000\u0000\u0000\u0000The oxone® salt in the presence of Ca2+ ions act as a mineralizing agent in the peptide bonds present in silk fibroin, altering some of its physical and chemical properties, such as zeta potential, crystallinity, micro-morphology, infrared spectroscopic profile, and showing formation or absence of SF original connections. \u0000\u0000\u0000\u0000The modified support was tested as a support alternative for the immobilization of Amano AK lipase from Pseudomonas fluorescens. Enzyme activity values indicated that lipase immobilization on SMF was efficient as a heterogeneous catalyst in the esterification of DDPO (deodorization distillate palm oil). \u0000\u0000\u0000\u0000The effect of some reaction parameters, such as catalyst concentration, molar ratio, temperature, and reaction time, was studied to optimize the conditions for maximum conversion of DDPO (40.5%).\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84518387","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 : 2021-03-17DOI: 10.2174/2211544710666210317160132
R. Fallahpour
Generally, it was assumed that Tebbe- and Takai-reagents are useful for methenylation reactions. Applying these reagents to aromatic ene dicarboxylates, unexpectedly the reduction of double bonds was achieved. There is, however, a different behaviour in both reagents. Takai-reagent yields reduction while Tebbe- reagent prefers isomerisation. It shows a selective and unique method to reduce a double bond of ene-dicarboxylates while both carboxylic groups are not affected at all. In addition, this method is easy and very cheap using Takai-reagent. If interested in just isomerisation, without any reduction of double bond, Tebbe-reagent can be applied. Due to our knowledge, such reactions were not published yet. We have shown a selective methodology to reduce aromatic ene-dicarboxylates with titanium ylides.
{"title":"Reduction of Aromatic Dimethyl Ene-Dicarboxylates to Dimethyl Succinates with Titanium Ylides","authors":"R. Fallahpour","doi":"10.2174/2211544710666210317160132","DOIUrl":"https://doi.org/10.2174/2211544710666210317160132","url":null,"abstract":"Generally, it was assumed that Tebbe- and Takai-reagents are useful for methenylation reactions. Applying these reagents to aromatic ene dicarboxylates, unexpectedly the reduction of double bonds was achieved. There is, however, a different behaviour in both reagents. Takai-reagent yields reduction while Tebbe- reagent prefers isomerisation. It shows a selective and unique method to reduce a double bond of ene-dicarboxylates while both carboxylic groups are not affected at all. In addition, this method is easy and very cheap using Takai-reagent. If interested in just isomerisation, without any reduction of double bond, Tebbe-reagent can be applied. Due to our knowledge, such reactions were not published yet. We have shown a selective methodology to reduce aromatic ene-dicarboxylates with titanium ylides.","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91338493","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 : 2021-02-15DOI: 10.2174/2211544710666210215094506
J. C. Marinho, E. G. Lima, T. L. Barbosa, M. Rodrigues
Increasing environmental pollution generated by fossil fuel consumption has intensified the consumption and development of renewable fuels. Thus, the aim of this work was to investigate the use of heterogeneous catalysts (SBA-15 and Al-SBA-15) for the transesterification of soybean oil to produce biodiesel. The pore size and surface acidity of SBA-15 were modified by the addition of heterogeneous Al atoms. Samples were characterized by X-ray diffraction, Nitrogen adsorption, Scanning electron microscopy, Infrared Spectroscopy, and Thermogravimetry. Results of the characterization study evidenced that a large amount of mesopore and surface acidity can significantly improve the transesterification reaction with the incorporation of aluminum into the SBA-15 framework. The best results were obtained with a 24 h reaction time and Al-SBA-15. The transesterification reaction of soybean oil with ethanol during 24 h showed in this work presented an efficient conversion of 85.5% with SBA-15 catalyst and 96.5% with the Al-SBA-15 catalyst.
{"title":"Biodiesel production by transesterification of soybean oil with ethanol using SBA-15 and Al-SBA-15 catalysts","authors":"J. C. Marinho, E. G. Lima, T. L. Barbosa, M. Rodrigues","doi":"10.2174/2211544710666210215094506","DOIUrl":"https://doi.org/10.2174/2211544710666210215094506","url":null,"abstract":"\u0000\u0000Increasing environmental pollution generated by fossil fuel consumption has intensified the consumption and development of renewable fuels. \u0000\u0000\u0000\u0000\u0000 Thus, the aim of this work was to investigate the use of heterogeneous catalysts (SBA-15 and Al-SBA-15) for the transesterification of soybean oil to produce biodiesel. \u0000\u0000\u0000\u0000The pore size and surface acidity of SBA-15 were modified by the addition of heterogeneous Al atoms. Samples were characterized by X-ray diffraction, Nitrogen adsorption, Scanning electron microscopy, Infrared Spectroscopy, and Thermogravimetry. \u0000\u0000\u0000\u0000 Results of the characterization study evidenced that a large amount of mesopore and surface acidity can significantly improve the transesterification reaction with the incorporation of aluminum into the SBA-15 framework. The best results were obtained with a 24 h reaction time and Al-SBA-15. The transesterification reaction of soybean oil with ethanol during 24 h showed in this work presented an efficient conversion of 85.5% with SBA-15 catalyst and 96.5% with the Al-SBA-15 catalyst.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73940153","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 : 2021-02-10DOI: 10.2174/2211544710666210210105039
A. Raza, S. Ravi, S. Tajudeen, K. I. Sheriff
Among the porous organic polymers, Covalent Triazine Polymers (CTPs) have emerged as an important class of materials with versatile applications such as energy storage and conversion, gas adsorption and separation, photocatalysis and heterogeneous catalysis. Particularly, CTPs have been often used as catalyst/catalyst support due to their excellent thermal and chemical stability, as well as recyclability in catalytic reactions. Moreover, the expanding methods available for the synthesis of CTPs, convenient functionalization and presence of nitrogen sites in the framework make them a suitable candidate to develop catalysts for organic transformations. In this review, the methods of synthesis, characterization of CTPs and mainly their applications as catalyst/catalyst support in organic transformations are summarized.
{"title":"Applications of Covalent Triazine Polymers in Catalytic Organic Transformations","authors":"A. Raza, S. Ravi, S. Tajudeen, K. I. Sheriff","doi":"10.2174/2211544710666210210105039","DOIUrl":"https://doi.org/10.2174/2211544710666210210105039","url":null,"abstract":"\u0000\u0000Among the porous organic polymers, Covalent Triazine Polymers (CTPs) have emerged as an important class of materials with versatile applications such as energy storage and conversion, gas adsorption and separation, photocatalysis and heterogeneous catalysis. Particularly, CTPs have been often used as catalyst/catalyst support due to their excellent thermal and chemical stability, as well as recyclability in catalytic reactions. Moreover, the expanding methods available for the synthesis of CTPs, convenient functionalization and presence of nitrogen sites in the framework make them a suitable candidate to develop catalysts for organic transformations. In this review, the methods of synthesis, characterization of CTPs and mainly their applications as catalyst/catalyst support in organic transformations are summarized.\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"458 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77030086","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 : 2021-01-27DOI: 10.2174/2211544710666210127092335
S. Ganesh, Kondabatini Sarika, P. Reddy, P. Padmaja
Betti base derivatives were employed as chiral ligands or as chiral auxiliaries in asymmetric transformations. In particular, N-alkyl Betti base derivatives are gaining importance as excellent ligands in asymmetric reactions. However there is no appropriate method exists for regioselective N-alkylation of Betti base. Therefore there is an urgent need to develop a new protocol for the regioselective N-alkylation of chiral Betti-base. An efficient method has been developed for one-pot synthesis of chiral N-alkyl Betti-base ligands from (S)-(+)-Betti base, arylglyoxals and cyclic 1,3-C,N-binucleophiles under catalyst free conditions. The chiral N-alkyl Betti-base ligands were obtained in good yields with excellent enantioselectivities. This method is a rapid, clean and does not require catalyst and chromatographic purification. We have developed an efficient one-pot three component strategy for the synthesis of new chiral N-alkyl Betti-base ligands from (S)-(+)-Betti base, arylglyoxals and cyclic 1,3-C,N-binucleophiles in the absence of catalyst.
在不对称转化中，贝蒂碱衍生物被用作手性配体或手性助剂。特别是，n -烷基Betti碱衍生物在不对称反应中作为优良的配体越来越重要。然而，目前尚无合适的区域选择性n -烷基化方法。因此，迫切需要开发一种新的手性betti碱的区域选择性n -烷基化方案。建立了一种在无催化剂条件下，由(S)-(+)- betti碱、芳基乙二醛和环1,3- c, n -二亲核试剂一锅法合成手性n -烷基betti碱配体的有效方法。手性n -烷基β -碱配体产率高，对映选择性好。该方法快速、清洁，不需要催化剂和色谱纯化。我们开发了一种高效的一锅三组分策略，在没有催化剂的情况下，由(S)-(+)- betti碱、芳基乙二醛和环1,3- c, n -双亲核试剂合成新的手性n -烷基betti碱配体。
{"title":"Synthesis of new chiral N-alkyl Betti-base ligands via one-pot three component strategy","authors":"S. Ganesh, Kondabatini Sarika, P. Reddy, P. Padmaja","doi":"10.2174/2211544710666210127092335","DOIUrl":"https://doi.org/10.2174/2211544710666210127092335","url":null,"abstract":"\u0000\u0000 Betti base derivatives were employed as chiral ligands or as chiral auxiliaries in asymmetric transformations. In particular, N-alkyl Betti base derivatives are gaining importance as excellent ligands in asymmetric reactions. However there is no appropriate method exists for regioselective N-alkylation of Betti base. Therefore there is an urgent need to develop a new protocol for the regioselective N-alkylation of chiral Betti-base.\u0000\u0000\u0000\u0000An efficient method has been developed for one-pot synthesis of chiral N-alkyl Betti-base ligands from (S)-(+)-Betti base, arylglyoxals and cyclic 1,3-C,N-binucleophiles under catalyst free conditions.\u0000\u0000\u0000\u0000 The chiral N-alkyl Betti-base ligands were obtained in good yields with excellent enantioselectivities. This method is a rapid, clean and does not require catalyst and chromatographic purification. \u0000\u0000\u0000\u0000 We have developed an efficient one-pot three component strategy for the synthesis of new chiral N-alkyl Betti-base ligands from (S)-(+)-Betti base, arylglyoxals and cyclic 1,3-C,N-binucleophiles in the absence of catalyst.\u0000\u0000","PeriodicalId":10862,"journal":{"name":"Current Catalysis","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86534515","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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