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Yoel Sasson - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of acetylenes via dehydrobromination using solid anhydrous Potassium Phosphate as the base under phase-transfer conditions
Tetrahedron Letters, 2012Co-Authors: Sanaa Shenawi-khalil, Sachin U. Sonavane, Yoel SassonAbstract:Abstract Phase-transfer catalyzed preparation of acetylenes from the corresponding vicinal dibromo compounds via double dehydrobromination using the mild solid base, anhydrous Potassium Phosphate, under very mild conditions is reported.
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Potassium Phosphate as a High-Performance Solid Base in Phase-Transfer-Catalyzed Alkylation Reactions
Industrial & Engineering Chemistry Research, 2007Co-Authors: Nida Qafisheh, Sudip Mukhopadhyay, Ashutosh V. Joshi, Yoel Sasson, Gaik-khuan Chuah, Stephan JaenickeAbstract:Potassium Phosphate is reported as a remarkably active and selective solid base in phase-transfer-catalyzed alkylation reactions of alkaline-sensitive substrates such as esters and halides. The performance of Potassium Phosphate exceeded that of common bases such as hydroxides, carbonates, fluorides, and oxides. Even though Potassium Phosphate is not porous and the number of basic sites exposed at the surface is relatively low (0.05 mequiv/g), it is still fully consumed in the alkylation process and converted into K2HPO4. The heterogeneous process follows a second-order rate law, and the rate constant was found to depend strongly on particle size, presence of water in the system, thermal pretreatment of the base, structure of the phase transfer catalyst, nature of the solvent, and reaction temperature. Some surface properties of K3PO4 have been determined and are discussed with relevance to the above catalytic alkylation reactions.
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Oxidative coupling of thiols to disulfides using a solid anhydrous Potassium Phosphate catalyst
Tetrahedron Letters, 2005Co-Authors: Ashutosh V. Joshi, Nida Qafisheh, Sudhakar R. Bhusare, Mubeen Baidossi, Yoel SassonAbstract:Thiols are oxidized to the corresponding disulfides with a mild base, anhydrous Potassium Phosphate, under ambient conditions in the presence of air.
Oriana Piermatti - One of the best experts on this subject based on the ideXlab platform.
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zirconium Potassium Phosphate methyl and or phenyl phosphonates as heterogeneous catalysts for knoevenagel condensation under solvent free conditions
Microporous and Mesoporous Materials, 2018Co-Authors: Ornelio Rosati, Daniela Lanari, Raffaella Scavo, Diana Persia, Fabio Marmottini, Morena Nocchetti, Massimo Curini, Oriana PiermattiAbstract:Abstract Three different basic zirconium Potassium Phosphate methyl and/or phenyl phosphonates of general formula Zr(PO3OK)2-(x+y)(PO3Me)x(PO3Ph)y namely ZrKP-Me, ZrKP-Ph and ZrKP-MePh have been prepared as amorphous solids. The catalytic activity of the solids was tested in the Knoevenagel condensation between several aldehydes with malononitrile and ethyl cyanoacetate in solvent free condition at room temperature and 50 °C, respectively. The hydrophobic groups on the solid catalysts surface favour reagent diffusion toward the basic sites increasing the catalytic activity of the prepared solids compared to the complete inorganic layered zirconium Potassium Phosphate, Zr(KPO4)2.
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Zirconium Potassium Phosphate methyl and/or phenyl phosphonates as heterogeneous catalysts for Knoevenagel condensation under solvent free conditions
Microporous and Mesoporous Materials, 2018Co-Authors: Ornelio Rosati, Daniela Lanari, Raffaella Scavo, Diana Persia, Fabio Marmottini, Morena Nocchetti, Massimo Curini, Oriana PiermattiAbstract:Abstract Three different basic zirconium Potassium Phosphate methyl and/or phenyl phosphonates of general formula Zr(PO3OK)2-(x+y)(PO3Me)x(PO3Ph)y namely ZrKP-Me, ZrKP-Ph and ZrKP-MePh have been prepared as amorphous solids. The catalytic activity of the solids was tested in the Knoevenagel condensation between several aldehydes with malononitrile and ethyl cyanoacetate in solvent free condition at room temperature and 50 °C, respectively. The hydrophobic groups on the solid catalysts surface favour reagent diffusion toward the basic sites increasing the catalytic activity of the prepared solids compared to the complete inorganic layered zirconium Potassium Phosphate, Zr(KPO4)2.
Joan De Pablo - One of the best experts on this subject based on the ideXlab platform.
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semi dynamic leaching tests of nickel containing wastes stabilized solidified with magnesium Potassium Phosphate cements
Journal of Hazardous Materials, 2011Co-Authors: Josep Torras, Irene Buj, Miquel Rovira, Joan De PabloAbstract:Abstract Herein is presented a study on the long-term leaching behaviour of nickel containing wastes stabilized/solidified with magnesium Potassium Phosphate cements. Two different semi-dynamic leaching tests were carried out on monolithic materials: ANS 16.1 test with liquid-to-solid ratio (L/S) of 10 dm 3 kg −1 and increasing renewal times, and ASTM C1308 test with liquid-to-solid ratio (L/S) of 100 dm 3 kg −1 and constant renewal time of 1 day. ASTM C1308 provides a lower degree of saturation of the leachant with respect to the leached material. The effectiveness of magnesium Potassium Phosphate cements for the inertization of nickel was proved. XRD analyses showed the presence of bobierrite on the monolith's surface after the leaching test, which had not been detected prior to the leaching test. In addition, the calculated cumulative release of the main components of the stabilization matrix (Mg 2+ , total P and K + ) was represented versus time in logarithmic scale and it was determined if the leaching mechanism corresponds to diffusion. Potassium is released by diffusion, while total phosphorous and magnesium show dissolution. Magnesium release in ANS 16.1 is slowed down because of saturation of the leachant. Experimental results demonstrate the importance of L/S ratio and renewal times in semi-dynamic leaching tests.
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Semi-dynamic leaching tests of nickel containing wastes stabilized/solidified with magnesium Potassium Phosphate cements.
Journal of Hazardous Materials, 2011Co-Authors: Josep Torras, Irene Buj, Miquel Rovira, Joan De PabloAbstract:Herein is presented a study on the long-term leaching behaviour of nickel containing wastes stabilized/solidified with magnesium Potassium Phosphate cements. Two different semi-dynamic leaching tests were carried out on monolithic materials: ANS 16.1 test with liquid-to-solid ratio (L/S) of 10 dm(3) kg(-1) and increasing renewal times, and ASTM C1308 test with liquid-to-solid ratio (L/S) of 100 dm(3) kg(-1) and constant renewal time of 1 day. ASTM C1308 provides a lower degree of saturation of the leachant with respect to the leached material. The effectiveness of magnesium Potassium Phosphate cements for the inertization of nickel was proved. XRD analyses showed the presence of bobierrite on the monolith's surface after the leaching test, which had not been detected prior to the leaching test. In addition, the calculated cumulative release of the main components of the stabilization matrix (Mg(2+), total P and K(+)) was represented versus time in logarithmic scale and it was determined if the leaching mechanism corresponds to diffusion. Potassium is released by diffusion, while total phosphorous and magnesium show dissolution. Magnesium release in ANS 16.1 is slowed down because of saturation of the leachant. Experimental results demonstrate the importance of L/S ratio and renewal times in semi-dynamic leaching tests.
Ornelio Rosati - One of the best experts on this subject based on the ideXlab platform.
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zirconium Potassium Phosphate methyl and or phenyl phosphonates as heterogeneous catalysts for knoevenagel condensation under solvent free conditions
Microporous and Mesoporous Materials, 2018Co-Authors: Ornelio Rosati, Daniela Lanari, Raffaella Scavo, Diana Persia, Fabio Marmottini, Morena Nocchetti, Massimo Curini, Oriana PiermattiAbstract:Abstract Three different basic zirconium Potassium Phosphate methyl and/or phenyl phosphonates of general formula Zr(PO3OK)2-(x+y)(PO3Me)x(PO3Ph)y namely ZrKP-Me, ZrKP-Ph and ZrKP-MePh have been prepared as amorphous solids. The catalytic activity of the solids was tested in the Knoevenagel condensation between several aldehydes with malononitrile and ethyl cyanoacetate in solvent free condition at room temperature and 50 °C, respectively. The hydrophobic groups on the solid catalysts surface favour reagent diffusion toward the basic sites increasing the catalytic activity of the prepared solids compared to the complete inorganic layered zirconium Potassium Phosphate, Zr(KPO4)2.
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Zirconium Potassium Phosphate methyl and/or phenyl phosphonates as heterogeneous catalysts for Knoevenagel condensation under solvent free conditions
Microporous and Mesoporous Materials, 2018Co-Authors: Ornelio Rosati, Daniela Lanari, Raffaella Scavo, Diana Persia, Fabio Marmottini, Morena Nocchetti, Massimo Curini, Oriana PiermattiAbstract:Abstract Three different basic zirconium Potassium Phosphate methyl and/or phenyl phosphonates of general formula Zr(PO3OK)2-(x+y)(PO3Me)x(PO3Ph)y namely ZrKP-Me, ZrKP-Ph and ZrKP-MePh have been prepared as amorphous solids. The catalytic activity of the solids was tested in the Knoevenagel condensation between several aldehydes with malononitrile and ethyl cyanoacetate in solvent free condition at room temperature and 50 °C, respectively. The hydrophobic groups on the solid catalysts surface favour reagent diffusion toward the basic sites increasing the catalytic activity of the prepared solids compared to the complete inorganic layered zirconium Potassium Phosphate, Zr(KPO4)2.
Massimo Curini - One of the best experts on this subject based on the ideXlab platform.
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zirconium Potassium Phosphate methyl and or phenyl phosphonates as heterogeneous catalysts for knoevenagel condensation under solvent free conditions
Microporous and Mesoporous Materials, 2018Co-Authors: Ornelio Rosati, Daniela Lanari, Raffaella Scavo, Diana Persia, Fabio Marmottini, Morena Nocchetti, Massimo Curini, Oriana PiermattiAbstract:Abstract Three different basic zirconium Potassium Phosphate methyl and/or phenyl phosphonates of general formula Zr(PO3OK)2-(x+y)(PO3Me)x(PO3Ph)y namely ZrKP-Me, ZrKP-Ph and ZrKP-MePh have been prepared as amorphous solids. The catalytic activity of the solids was tested in the Knoevenagel condensation between several aldehydes with malononitrile and ethyl cyanoacetate in solvent free condition at room temperature and 50 °C, respectively. The hydrophobic groups on the solid catalysts surface favour reagent diffusion toward the basic sites increasing the catalytic activity of the prepared solids compared to the complete inorganic layered zirconium Potassium Phosphate, Zr(KPO4)2.
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Zirconium Potassium Phosphate methyl and/or phenyl phosphonates as heterogeneous catalysts for Knoevenagel condensation under solvent free conditions
Microporous and Mesoporous Materials, 2018Co-Authors: Ornelio Rosati, Daniela Lanari, Raffaella Scavo, Diana Persia, Fabio Marmottini, Morena Nocchetti, Massimo Curini, Oriana PiermattiAbstract:Abstract Three different basic zirconium Potassium Phosphate methyl and/or phenyl phosphonates of general formula Zr(PO3OK)2-(x+y)(PO3Me)x(PO3Ph)y namely ZrKP-Me, ZrKP-Ph and ZrKP-MePh have been prepared as amorphous solids. The catalytic activity of the solids was tested in the Knoevenagel condensation between several aldehydes with malononitrile and ethyl cyanoacetate in solvent free condition at room temperature and 50 °C, respectively. The hydrophobic groups on the solid catalysts surface favour reagent diffusion toward the basic sites increasing the catalytic activity of the prepared solids compared to the complete inorganic layered zirconium Potassium Phosphate, Zr(KPO4)2.