In this study, titanium dioxide (TiO2) and titanium dioxide – activated carbon composite (TiO2–AC... more In this study, titanium dioxide (TiO2) and titanium dioxide – activated carbon composite (TiO2–AC) were prepared by sol-gel method for photoelectrochemical (PEC) applications. Characterization of the materials was performed by scanning electron microscope, energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, X-ray diffraction, and diffuse reflectance spectroscopy. The results show that TiO2 was successfully loaded on activated carbon (AC), producing TiO2–AC with 2.61 eV of bandgap energy, lower than that of TiO2 (3.15 eV). Photoanodes based on TiO2 and TiO2–AC were fabricated and applied to PEC experiments for phenol degradation. In comparison with the TiO2 photoanode, the TiO2–AC one exhibited superior photocatalytic activity, which was indicated by a high current density and effective phenol removal. A mechanism of phenol PEC degradation on the TiO2–AC photoanode was proposed, which includes interaction between protonated phenol and active sites bearing oxyge...
The reduction of aldehydes and ketones based on MPV chemistry is one of the vital transformations... more The reduction of aldehydes and ketones based on MPV chemistry is one of the vital transformations in organic chemistry. In this study, MPV chemistry was developed in heating assistance of Microwave to synthesize a broad range of alcohol with yields up to 96 % by a simple, cheap, and safe synthetic protocol. Sodium hydroxide (NaOH) is an excellent promoter for the reduction. The method is quite cheap and straightforward while it utilized easy-to-handle chemicals and did not require strictly anhydrous reagents, transition metals, or any additional ligands. This potential method encourages a scale-up upgrading of Microwave use for alcohol production.
The carbonyl–olefin metathesis (COM) reaction is a highly valuable chemical transformation in a b... more The carbonyl–olefin metathesis (COM) reaction is a highly valuable chemical transformation in a broad range of applications. However, its scope is much less explored compared to analogous olefin–olefin metathesis reactions. Herein we demonstrate the use of tropylium ion as a new effective organic Lewis acid catalyst for both intramolecular and intermolecular COM and new ring-opening metathesis reactions. This represents a significant improvement in substrate scope from recently reported developments in this field.
The carbonyl-olefin metathesis (COM) reaction is a highly valuable chemical transformation in a b... more The carbonyl-olefin metathesis (COM) reaction is a highly valuable chemical transformation in a broad range of applications. However, its scope is much less explored compared to analogous olefin-olefin metathesis reactions. Herein we demonstrate the use of tropylium ion as a new effective organic Lewis acid catalyst for both intramolecular and intermolecular COM and new ring-opening metathesis reactions. This represents a significant improvement in substrate scope from recently reported developments in this field.
The Wittig-type chemical procedure is adapted to efficiently facilitate alkyl–alkyl coupling reac... more The Wittig-type chemical procedure is adapted to efficiently facilitate alkyl–alkyl coupling reactions in batch and flow.
The carbonyl-olefin metathesis reaction is a synthetically valuable transformation that could fac... more The carbonyl-olefin metathesis reaction is a synthetically valuable transformation that could facilitate rapid functional group interconversion and construction of new organic structures. Herein we demonstrate that elemental iodine, a very simple and mild catalyst, can efficiently promote this chemical transformation under mild reaction conditions with excellent outcomes. Our mechanistic studies revealed intriguing aspects of iodine activation mode that could change the previously established perception of catalyst and substrate design for the carbonyl-olefin metathesis reaction.
The synthesis of trifluoromethylated cyclopropenes is very important for applications in drug dis... more The synthesis of trifluoromethylated cyclopropenes is very important for applications in drug discovery and functional materials. In this report, we describe the application of readily available, chiral rhodium(II) catalysts in a highly efficient asymmetric cyclopropenation reaction of fluorinated donor-acceptor diazoalkanes using a broad variety of aliphatic and aromatic alkynes. Further studies highlight the unique reactivity of fluorinated donor-acceptor diazoalkanes in the synthesis of oligo-cyclopropenes. Subsequent C-H functionalization of trifluoromethyl cyclopropenes furnishes densely substituted cyclopropene frameworks and also allows the synthesis of bis-cyclopropenes.<br>
Biorefineries from paddy residues (rice straw and rice husk) have a high potential to satisfy hum... more Biorefineries from paddy residues (rice straw and rice husk) have a high potential to satisfy human society’s need for sustainable fuel and chemical production. Biorefinery systems should be created in a sustainable and eco-friendly manner, accompanying the safe disposal of waste stream produced during processing. This study developed a pilot-scale biorefinery, whose bioethanol production from rice straw was an integrated recovery system for lignin, silica, and nutrient recovery. The recovery yield of silica and lignin from the black liquor of alkaline pretreatment was up to 96%, and the lignin purity reached 79% without the existence of carbohydrate fiber. After the recovery, the final liquid waste mainly contained inorganic matters and has a potential to be reused in the acidification step. The distillation residue was a nitrogen source for simultaneous saccharification and fermentation equivalent to corn steep liquor with the final ethanol concentration of 1.6 wt% in 160 h. The new process can be considered as a zero-waste biorefinery model. The material flow indicated that more valued products produced by the simple method increase the profits of this process. Also, the energy efficiency of the process was 0.53 that demonstrated the process’s economy and sustainability. The proposed system was feasible to foster the sustainable integration of local agricultural development and biomass industry shortly.
Substituted pyrans and furans are core structures found in a wide variety of natural products and... more Substituted pyrans and furans are core structures found in a wide variety of natural products and biologically-active compounds. Herein, we report a practical and mild catalytic method for the synthesis of substituted pyrans and furans using molecular iodine, a simple and inexpensive catalyst. The method described herein is performed in solvent-free conditions in ambient temperature and atmosphere, thus offering a facile and green alternative to currently available reaction protocols. A combination of experimental studies and high‐level DFT calculations revealed interesting mechanistic insights of this seemingly simple reaction.
Tropylium bromide undergoes non-catalyzed, regioselective additions to a large variety of Michael... more Tropylium bromide undergoes non-catalyzed, regioselective additions to a large variety of Michael acceptors. In this way, acrylic esters are converted into ß-bromo-α-cycloheptatrienyl-propionic esters. The reactions are interpreted by nucleophilic attack of bromide ions at the electron-deficient olefins and trapping of the incipient carbanion by the tropylium ion. Quantum chemical calculations were performed to elucidate the analogy to the amine or phosphine-catalyzed Rauhut-Currier reactions. Subsequent synthetic transformations of the bromo-cycloheptatrienylated adducts are reported.
Bi2O3 was proven an attractive compound for electrode modification in heavy metal electrochemical... more Bi2O3 was proven an attractive compound for electrode modification in heavy metal electrochemical analysis. A novel method for synthesizing Bi2O3-attached multiwalled carbon nanotubes (Bi2O3@CNTs) in solution is successfully developed in this study. Characteristics of the obtained Bi2O3@CNTs were proven by modern techniques such as X-ray diffraction, Raman spectroscopy, scanning electronic microscopy, transmission electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and anodic stripping voltammetry. Microscopy images and spectra results reveal that Bi2O3 particles are mainly attached at defect points on multiwalled carbon nanotubes (MWCNTs) walls. Paste electrodes based on the MWCNTs and synthesized Bi2O3@CNTs were applied for electrochemical measurements. The redox mechanism of Bi2O3 on the electrode surface was also made clear by the cyclic voltammetric tests. The recorded cyclic voltammograms and electrochemical impedance spectroscopy demonstrate that ...
In this study, titanium dioxide (TiO2) and titanium dioxide – activated carbon composite (TiO2–AC... more In this study, titanium dioxide (TiO2) and titanium dioxide – activated carbon composite (TiO2–AC) were prepared by sol-gel method for photoelectrochemical (PEC) applications. Characterization of the materials was performed by scanning electron microscope, energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, X-ray diffraction, and diffuse reflectance spectroscopy. The results show that TiO2 was successfully loaded on activated carbon (AC), producing TiO2–AC with 2.61 eV of bandgap energy, lower than that of TiO2 (3.15 eV). Photoanodes based on TiO2 and TiO2–AC were fabricated and applied to PEC experiments for phenol degradation. In comparison with the TiO2 photoanode, the TiO2–AC one exhibited superior photocatalytic activity, which was indicated by a high current density and effective phenol removal. A mechanism of phenol PEC degradation on the TiO2–AC photoanode was proposed, which includes interaction between protonated phenol and active sites bearing oxyge...
The reduction of aldehydes and ketones based on MPV chemistry is one of the vital transformations... more The reduction of aldehydes and ketones based on MPV chemistry is one of the vital transformations in organic chemistry. In this study, MPV chemistry was developed in heating assistance of Microwave to synthesize a broad range of alcohol with yields up to 96 % by a simple, cheap, and safe synthetic protocol. Sodium hydroxide (NaOH) is an excellent promoter for the reduction. The method is quite cheap and straightforward while it utilized easy-to-handle chemicals and did not require strictly anhydrous reagents, transition metals, or any additional ligands. This potential method encourages a scale-up upgrading of Microwave use for alcohol production.
The carbonyl–olefin metathesis (COM) reaction is a highly valuable chemical transformation in a b... more The carbonyl–olefin metathesis (COM) reaction is a highly valuable chemical transformation in a broad range of applications. However, its scope is much less explored compared to analogous olefin–olefin metathesis reactions. Herein we demonstrate the use of tropylium ion as a new effective organic Lewis acid catalyst for both intramolecular and intermolecular COM and new ring-opening metathesis reactions. This represents a significant improvement in substrate scope from recently reported developments in this field.
The carbonyl-olefin metathesis (COM) reaction is a highly valuable chemical transformation in a b... more The carbonyl-olefin metathesis (COM) reaction is a highly valuable chemical transformation in a broad range of applications. However, its scope is much less explored compared to analogous olefin-olefin metathesis reactions. Herein we demonstrate the use of tropylium ion as a new effective organic Lewis acid catalyst for both intramolecular and intermolecular COM and new ring-opening metathesis reactions. This represents a significant improvement in substrate scope from recently reported developments in this field.
The Wittig-type chemical procedure is adapted to efficiently facilitate alkyl–alkyl coupling reac... more The Wittig-type chemical procedure is adapted to efficiently facilitate alkyl–alkyl coupling reactions in batch and flow.
The carbonyl-olefin metathesis reaction is a synthetically valuable transformation that could fac... more The carbonyl-olefin metathesis reaction is a synthetically valuable transformation that could facilitate rapid functional group interconversion and construction of new organic structures. Herein we demonstrate that elemental iodine, a very simple and mild catalyst, can efficiently promote this chemical transformation under mild reaction conditions with excellent outcomes. Our mechanistic studies revealed intriguing aspects of iodine activation mode that could change the previously established perception of catalyst and substrate design for the carbonyl-olefin metathesis reaction.
The synthesis of trifluoromethylated cyclopropenes is very important for applications in drug dis... more The synthesis of trifluoromethylated cyclopropenes is very important for applications in drug discovery and functional materials. In this report, we describe the application of readily available, chiral rhodium(II) catalysts in a highly efficient asymmetric cyclopropenation reaction of fluorinated donor-acceptor diazoalkanes using a broad variety of aliphatic and aromatic alkynes. Further studies highlight the unique reactivity of fluorinated donor-acceptor diazoalkanes in the synthesis of oligo-cyclopropenes. Subsequent C-H functionalization of trifluoromethyl cyclopropenes furnishes densely substituted cyclopropene frameworks and also allows the synthesis of bis-cyclopropenes.<br>
Biorefineries from paddy residues (rice straw and rice husk) have a high potential to satisfy hum... more Biorefineries from paddy residues (rice straw and rice husk) have a high potential to satisfy human society’s need for sustainable fuel and chemical production. Biorefinery systems should be created in a sustainable and eco-friendly manner, accompanying the safe disposal of waste stream produced during processing. This study developed a pilot-scale biorefinery, whose bioethanol production from rice straw was an integrated recovery system for lignin, silica, and nutrient recovery. The recovery yield of silica and lignin from the black liquor of alkaline pretreatment was up to 96%, and the lignin purity reached 79% without the existence of carbohydrate fiber. After the recovery, the final liquid waste mainly contained inorganic matters and has a potential to be reused in the acidification step. The distillation residue was a nitrogen source for simultaneous saccharification and fermentation equivalent to corn steep liquor with the final ethanol concentration of 1.6 wt% in 160 h. The new process can be considered as a zero-waste biorefinery model. The material flow indicated that more valued products produced by the simple method increase the profits of this process. Also, the energy efficiency of the process was 0.53 that demonstrated the process’s economy and sustainability. The proposed system was feasible to foster the sustainable integration of local agricultural development and biomass industry shortly.
Substituted pyrans and furans are core structures found in a wide variety of natural products and... more Substituted pyrans and furans are core structures found in a wide variety of natural products and biologically-active compounds. Herein, we report a practical and mild catalytic method for the synthesis of substituted pyrans and furans using molecular iodine, a simple and inexpensive catalyst. The method described herein is performed in solvent-free conditions in ambient temperature and atmosphere, thus offering a facile and green alternative to currently available reaction protocols. A combination of experimental studies and high‐level DFT calculations revealed interesting mechanistic insights of this seemingly simple reaction.
Tropylium bromide undergoes non-catalyzed, regioselective additions to a large variety of Michael... more Tropylium bromide undergoes non-catalyzed, regioselective additions to a large variety of Michael acceptors. In this way, acrylic esters are converted into ß-bromo-α-cycloheptatrienyl-propionic esters. The reactions are interpreted by nucleophilic attack of bromide ions at the electron-deficient olefins and trapping of the incipient carbanion by the tropylium ion. Quantum chemical calculations were performed to elucidate the analogy to the amine or phosphine-catalyzed Rauhut-Currier reactions. Subsequent synthetic transformations of the bromo-cycloheptatrienylated adducts are reported.
Bi2O3 was proven an attractive compound for electrode modification in heavy metal electrochemical... more Bi2O3 was proven an attractive compound for electrode modification in heavy metal electrochemical analysis. A novel method for synthesizing Bi2O3-attached multiwalled carbon nanotubes (Bi2O3@CNTs) in solution is successfully developed in this study. Characteristics of the obtained Bi2O3@CNTs were proven by modern techniques such as X-ray diffraction, Raman spectroscopy, scanning electronic microscopy, transmission electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and anodic stripping voltammetry. Microscopy images and spectra results reveal that Bi2O3 particles are mainly attached at defect points on multiwalled carbon nanotubes (MWCNTs) walls. Paste electrodes based on the MWCNTs and synthesized Bi2O3@CNTs were applied for electrochemical measurements. The redox mechanism of Bi2O3 on the electrode surface was also made clear by the cyclic voltammetric tests. The recorded cyclic voltammograms and electrochemical impedance spectroscopy demonstrate that ...
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