The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform
Hossein Reza Darabi - One of the best experts on this subject based on the ideXlab platform.
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Microwave-induced calcium(II) chloride-catalyzed Paal–Knorr Pyrrole Synthesis: a safe, expeditious, and sustainable protocol
Research on Chemical Intermediates, 2018Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Saeed RastgarAbstract:Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free Synthesis of Pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst. Graphical abstract
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microwave induced calcium ii chloride catalyzed paal Knorr Pyrrole Synthesis a safe expeditious and sustainable protocol
Research on Chemical Intermediates, 2018Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Saeed RastgarAbstract:Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free Synthesis of Pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst.
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l-Tryptophan-catalyzed Paal–Knorr Pyrrole cyclocondensation: an efficient, clean and recyclable organocatalyst
Research on Chemical Intermediates, 2016Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Hani Sayahi, Yadollah BalavarAbstract:A simple, clean, and efficient solvent-free protocol is introduced for Paal–Knorr Pyrrole Synthesis catalyzed by l -tryptophan as a thermally resistant, natural primary amino acid. The products were obtained mostly in excellent yields through the reaction of hexane-2,5-dione with aromatic primary amines bearing a variety of substituents. The catalyst could be easily isolated from the reaction mixture and recycled at least six times without significant loss of activity. The procedure has an environmentally benign nature in agreement with the concepts of green chemistry.
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Catalytic activity of the nanoporous MCM-41 surface for the Paal–Knorr Pyrrole cyclocondensation
Zeitschrift für Naturforschung B, 2015Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Mostafa M. Amini, Khosrow Jadidi, Hossein Reza DarabiAbstract:AbstractThe investigation of different oxide surfaces revealed that nanoporous silica (MCM-41) had the best catalytic activity for Paal–Knorr Pyrrole Synthesis. Despite the same composition, MCM-41 proved to be more effective than SiO2 itself, probably due to a significantly higher surface area of the SiO2 nanopores. The important features of this “clean” solvent-free protocol are the ease of recovery and the reuse of the catalyst for several cycles, operational simplicity, and easy product isolation and purification.
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Vitamin B_1 as a metal-free organocatalyst for greener Paal–Knorr Pyrrole Synthesis
Environmental Chemistry Letters, 2012Co-Authors: Hossein Reza Darabi, Kioumars Aghapoor, Abbas Darestani Farahani, Farshid MohsenzadehAbstract:This investigation discloses a greener reaction to prepare Pyrrole derivatives. Metal-free catalysts are greener alternatives to existing metal catalysts in synthetic organic chemistry. Indeed, transition metals are often costly and toxic. They may be found as traces in health reaction products such as pharmaceuticals. Alternatively small organic molecules termed “organocatalysts” allow the Synthesis of valuable products without traces of toxic metals. Here, we show for the first time the use of vitamin B_1 as new organocatalyst for the Paal–Knorr Pyrrole Synthesis under ambient conditions. Reaction conditions were optimized for the reaction of hexane-2,5-dione with 4-methoxyaniline. Ethanol was the most effective solvent. The conversion was quantitative using vitamin B_1, by comparison with a low yield of 30 % without catalysis. The best conditions were performed in ethanol with 5 mol % of vitamin B_1 during 1 h. This reaction was tested using various aromatic amines. To conclude the use of vitamin B_1 for the Paal–Knorr Pyrrole, cyclocondensation has mild reaction conditions, is simple to perform, and gives moderate to excellent yields. It is therefore a promising reaction for the preparation of various Pyrrole derivatives.
Farshid Mohsenzadeh - One of the best experts on this subject based on the ideXlab platform.
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Microwave-induced calcium(II) chloride-catalyzed Paal–Knorr Pyrrole Synthesis: a safe, expeditious, and sustainable protocol
Research on Chemical Intermediates, 2018Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Saeed RastgarAbstract:Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free Synthesis of Pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst. Graphical abstract
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microwave induced calcium ii chloride catalyzed paal Knorr Pyrrole Synthesis a safe expeditious and sustainable protocol
Research on Chemical Intermediates, 2018Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Saeed RastgarAbstract:Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free Synthesis of Pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst.
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l-Tryptophan-catalyzed Paal–Knorr Pyrrole cyclocondensation: an efficient, clean and recyclable organocatalyst
Research on Chemical Intermediates, 2016Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Hani Sayahi, Yadollah BalavarAbstract:A simple, clean, and efficient solvent-free protocol is introduced for Paal–Knorr Pyrrole Synthesis catalyzed by l -tryptophan as a thermally resistant, natural primary amino acid. The products were obtained mostly in excellent yields through the reaction of hexane-2,5-dione with aromatic primary amines bearing a variety of substituents. The catalyst could be easily isolated from the reaction mixture and recycled at least six times without significant loss of activity. The procedure has an environmentally benign nature in agreement with the concepts of green chemistry.
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Catalytic activity of the nanoporous MCM-41 surface for the Paal–Knorr Pyrrole cyclocondensation
Zeitschrift für Naturforschung B, 2015Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Mostafa M. Amini, Khosrow Jadidi, Hossein Reza DarabiAbstract:AbstractThe investigation of different oxide surfaces revealed that nanoporous silica (MCM-41) had the best catalytic activity for Paal–Knorr Pyrrole Synthesis. Despite the same composition, MCM-41 proved to be more effective than SiO2 itself, probably due to a significantly higher surface area of the SiO2 nanopores. The important features of this “clean” solvent-free protocol are the ease of recovery and the reuse of the catalyst for several cycles, operational simplicity, and easy product isolation and purification.
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Vitamin B_1 as a metal-free organocatalyst for greener Paal–Knorr Pyrrole Synthesis
Environmental Chemistry Letters, 2012Co-Authors: Hossein Reza Darabi, Kioumars Aghapoor, Abbas Darestani Farahani, Farshid MohsenzadehAbstract:This investigation discloses a greener reaction to prepare Pyrrole derivatives. Metal-free catalysts are greener alternatives to existing metal catalysts in synthetic organic chemistry. Indeed, transition metals are often costly and toxic. They may be found as traces in health reaction products such as pharmaceuticals. Alternatively small organic molecules termed “organocatalysts” allow the Synthesis of valuable products without traces of toxic metals. Here, we show for the first time the use of vitamin B_1 as new organocatalyst for the Paal–Knorr Pyrrole Synthesis under ambient conditions. Reaction conditions were optimized for the reaction of hexane-2,5-dione with 4-methoxyaniline. Ethanol was the most effective solvent. The conversion was quantitative using vitamin B_1, by comparison with a low yield of 30 % without catalysis. The best conditions were performed in ethanol with 5 mol % of vitamin B_1 during 1 h. This reaction was tested using various aromatic amines. To conclude the use of vitamin B_1 for the Paal–Knorr Pyrrole, cyclocondensation has mild reaction conditions, is simple to perform, and gives moderate to excellent yields. It is therefore a promising reaction for the preparation of various Pyrrole derivatives.
Kioumars Aghapoor - One of the best experts on this subject based on the ideXlab platform.
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Microwave-induced calcium(II) chloride-catalyzed Paal–Knorr Pyrrole Synthesis: a safe, expeditious, and sustainable protocol
Research on Chemical Intermediates, 2018Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Saeed RastgarAbstract:Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free Synthesis of Pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst. Graphical abstract
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microwave induced calcium ii chloride catalyzed paal Knorr Pyrrole Synthesis a safe expeditious and sustainable protocol
Research on Chemical Intermediates, 2018Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Saeed RastgarAbstract:Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free Synthesis of Pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst.
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l-Tryptophan-catalyzed Paal–Knorr Pyrrole cyclocondensation: an efficient, clean and recyclable organocatalyst
Research on Chemical Intermediates, 2016Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Hani Sayahi, Yadollah BalavarAbstract:A simple, clean, and efficient solvent-free protocol is introduced for Paal–Knorr Pyrrole Synthesis catalyzed by l -tryptophan as a thermally resistant, natural primary amino acid. The products were obtained mostly in excellent yields through the reaction of hexane-2,5-dione with aromatic primary amines bearing a variety of substituents. The catalyst could be easily isolated from the reaction mixture and recycled at least six times without significant loss of activity. The procedure has an environmentally benign nature in agreement with the concepts of green chemistry.
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Catalytic activity of the nanoporous MCM-41 surface for the Paal–Knorr Pyrrole cyclocondensation
Zeitschrift für Naturforschung B, 2015Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Mostafa M. Amini, Khosrow Jadidi, Hossein Reza DarabiAbstract:AbstractThe investigation of different oxide surfaces revealed that nanoporous silica (MCM-41) had the best catalytic activity for Paal–Knorr Pyrrole Synthesis. Despite the same composition, MCM-41 proved to be more effective than SiO2 itself, probably due to a significantly higher surface area of the SiO2 nanopores. The important features of this “clean” solvent-free protocol are the ease of recovery and the reuse of the catalyst for several cycles, operational simplicity, and easy product isolation and purification.
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Vitamin B_1 as a metal-free organocatalyst for greener Paal–Knorr Pyrrole Synthesis
Environmental Chemistry Letters, 2012Co-Authors: Hossein Reza Darabi, Kioumars Aghapoor, Abbas Darestani Farahani, Farshid MohsenzadehAbstract:This investigation discloses a greener reaction to prepare Pyrrole derivatives. Metal-free catalysts are greener alternatives to existing metal catalysts in synthetic organic chemistry. Indeed, transition metals are often costly and toxic. They may be found as traces in health reaction products such as pharmaceuticals. Alternatively small organic molecules termed “organocatalysts” allow the Synthesis of valuable products without traces of toxic metals. Here, we show for the first time the use of vitamin B_1 as new organocatalyst for the Paal–Knorr Pyrrole Synthesis under ambient conditions. Reaction conditions were optimized for the reaction of hexane-2,5-dione with 4-methoxyaniline. Ethanol was the most effective solvent. The conversion was quantitative using vitamin B_1, by comparison with a low yield of 30 % without catalysis. The best conditions were performed in ethanol with 5 mol % of vitamin B_1 during 1 h. This reaction was tested using various aromatic amines. To conclude the use of vitamin B_1 for the Paal–Knorr Pyrrole, cyclocondensation has mild reaction conditions, is simple to perform, and gives moderate to excellent yields. It is therefore a promising reaction for the preparation of various Pyrrole derivatives.
Yadollah Balavar - One of the best experts on this subject based on the ideXlab platform.
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l-Tryptophan-catalyzed Paal–Knorr Pyrrole cyclocondensation: an efficient, clean and recyclable organocatalyst
Research on Chemical Intermediates, 2016Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Hossein Reza Darabi, Hani Sayahi, Yadollah BalavarAbstract:A simple, clean, and efficient solvent-free protocol is introduced for Paal–Knorr Pyrrole Synthesis catalyzed by l -tryptophan as a thermally resistant, natural primary amino acid. The products were obtained mostly in excellent yields through the reaction of hexane-2,5-dione with aromatic primary amines bearing a variety of substituents. The catalyst could be easily isolated from the reaction mixture and recycled at least six times without significant loss of activity. The procedure has an environmentally benign nature in agreement with the concepts of green chemistry.
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silica supported bismuth iii chloride as a new recyclable heterogeneous catalyst for the paal Knorr Pyrrole Synthesis
ChemInform, 2012Co-Authors: Kioumars Aghapoor, Leila Ebadinia, Farshid Mohsenzadeh, Mina Mohebi Morad, Yadollah Balavar, Hossein Reza DarabiAbstract:The catalyst system exhibits a remarkable reusable activity and a higher performance compared to homogeneous BiCl3.
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Silica-Supported Bismuth(III) Chloride as a New Recyclable Heterogeneous Catalyst for the Paal—Knorr Pyrrole Synthesis.
ChemInform, 2012Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Mina Mohebi Morad, Yadollah Balavar, Leila Ebadi-nia, Hossein Reza DarabiAbstract:The catalyst system exhibits a remarkable reusable activity and a higher performance compared to homogeneous BiCl3.
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silica supported bismuth iii chloride as a new recyclable heterogeneous catalyst for the paal Knorr Pyrrole Synthesis
Journal of Organometallic Chemistry, 2012Co-Authors: Kioumars Aghapoor, Leila Ebadinia, Farshid Mohsenzadeh, Mina Mohebi Morad, Yadollah Balavar, Hossein Reza DarabiAbstract:Abstract Silica-supported bismuth(III) chloride (BiCl 3 /SiO 2 ) acts as as a highly efficient heterogeneous Lewis acid catalyst for the Paal–Knorr Pyrrole Synthesis in hexane at room temperature. The catalyst exhibited remarkable reusable activity and higher catalytic performance than homogeneous BiCl 3 . A plausible mechanism for the catalytic action of BiCl 3 /SiO 2 has been introduced.
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Silica-supported bismuth(III) chloride as a new recyclable heterogeneous catalyst for the Paal–Knorr Pyrrole Synthesis
Journal of Organometallic Chemistry, 2012Co-Authors: Kioumars Aghapoor, Farshid Mohsenzadeh, Mina Mohebi Morad, Yadollah Balavar, Leila Ebadi-nia, Hossein Reza DarabiAbstract:Abstract Silica-supported bismuth(III) chloride (BiCl 3 /SiO 2 ) acts as as a highly efficient heterogeneous Lewis acid catalyst for the Paal–Knorr Pyrrole Synthesis in hexane at room temperature. The catalyst exhibited remarkable reusable activity and higher catalytic performance than homogeneous BiCl 3 . A plausible mechanism for the catalytic action of BiCl 3 /SiO 2 has been introduced.
Hajar Mahmoudi - One of the best experts on this subject based on the ideXlab platform.
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Room temperature aqueous Paal–Knorr Pyrrole Synthesis catalyzed by aluminum tris(dodecyl sulfate)trihydrate
Environmental Chemistry Letters, 2013Co-Authors: Abbas Ali Jafari, Hajar MahmoudiAbstract:This article reports a novel procedure to prepare Pyrroles using a modification of the Paal–Knorr reaction. Water is a safe solvent meeting environmental considerations, but most organic substrates are not soluble in water. A possible solution to improve the solubility of substrates is the use of surface-active reagents that can form micelles. For instance, combined Lewis acid–surfactant catalyst acts both as a Lewis acid to activate the substrate molecules and as a surfactant to form emulsions in water. Here, we prepared and used aluminum tris(dodecyl sulfate)trihydrate to condense various amines to 2,5-hexadione at room temperature. The sole solid Pyrrole was separated by a simple filtration. Our findings thus show a novel and improved modification of the Paal–Knorr reaction in terms of mild reaction conditions and clean reaction profiles, using a simple workup procedure and improved yields with excellent chemo-selectivity.
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room temperature aqueous paal Knorr Pyrrole Synthesis catalyzed by aluminum tris dodecyl sulfate trihydrate
Environmental Chemistry Letters, 2013Co-Authors: Abbas Ali Jafari, Hajar MahmoudiAbstract:This article reports a novel procedure to prepare Pyrroles using a modification of the Paal–Knorr reaction. Water is a safe solvent meeting environmental considerations, but most organic substrates are not soluble in water. A possible solution to improve the solubility of substrates is the use of surface-active reagents that can form micelles. For instance, combined Lewis acid–surfactant catalyst acts both as a Lewis acid to activate the substrate molecules and as a surfactant to form emulsions in water. Here, we prepared and used aluminum tris(dodecyl sulfate)trihydrate to condense various amines to 2,5-hexadione at room temperature. The sole solid Pyrrole was separated by a simple filtration. Our findings thus show a novel and improved modification of the Paal–Knorr reaction in terms of mild reaction conditions and clean reaction profiles, using a simple workup procedure and improved yields with excellent chemo-selectivity.
