The Experts below are selected from a list of 495 Experts worldwide ranked by ideXlab platform
Maaroof Zarei - One of the best experts on this subject based on the ideXlab platform.
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Oxidative N-deprotection of 2-azetidinones using silver(II)–persulfate complexes as a twin oxidant/co-oxidant
Tetrahedron Letters, 2013Co-Authors: Maaroof ZareiAbstract:Abstract N - p -Methoxyphenyl, N - p -ethoxyphenyl, N -4-methoxynaphth-1-yl, and N - p -methoxybenzyl 2-azetidinones readily undergo oxidative N -Dearylation to afford NH-2-azetidinones using a silver(II)–persulfate complex. The ease of preparation and stability of the reagents, neutrality of the reaction medium, fast conversions, good-to-excellent yields of products, and the mildness of the reaction conditions are some advantages of this method.
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On-column N-Dearylation of 2-azetidinones by silica-supported ceric ammonium nitrate
Tetrahedron, 2012Co-Authors: Maaroof Zarei, Aliasghar Jarrahpour, Edris Ebrahimi, Malihe Aye, Seid Ali Torabi BadrabadyAbstract:A modified traditional preparative chromatographic column can be used to achieve quantitative N-Dearylation of N-(alkoxyphenyl), N-(alkoxynaphthyl), and N-(alkoxybenzyl)-2-azetidinones under mild conditions. Starting materials are charged on top of the column and the pure N-unsubstituted 2-azetidinones leave the column minutes later without need for other purifications. The yields are good-to-excellent and the reaction condition is mild, easy, efficient, and cheap.
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Argentic Oxide Mediated N-Dearylation of β-Lactams.
ChemInform, 2011Co-Authors: Maaroof Zarei, Aliasghar JarrahpourAbstract:The use of AgO allows a simple and efficient process which affords, compared to CAN, similar yields within a shorter time (10 min versus 45 min).
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Argentic oxide mediated N-Dearylation of β-lactams
Tetrahedron Letters, 2011Co-Authors: Maaroof Zarei, Aliasghar JarrahpourAbstract:Abstract A method is described for the N-Dearylation of N -(4-methoxy- or 4-ethoxyphenyl)-2-azetidinones with argentic oxide. The yields are good-to-excellent and the reaction is simple, efficient, and fast.
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Synthesis of N-unsubstituted β-lactams from N-alkoxyphenyl-β-lactams with cobalt(III) fluoride
Tetrahedron Letters, 2010Co-Authors: Maaroof Zarei, Aliasghar JarrahpourAbstract:Mild and efficient oxidative N-Dearylation of N-alkoxyphenyl-β-lactams with cobalt(III) fluoride proceeded in good to excellent yields to afford the corresponding N-unsubstituted β-lactams. Optimization of the solvent, molar ratio of reagents, time, and temperature are described.
Aliasghar Jarrahpour - One of the best experts on this subject based on the ideXlab platform.
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On-column N-Dearylation of 2-azetidinones by silica-supported ceric ammonium nitrate
Tetrahedron, 2012Co-Authors: Maaroof Zarei, Aliasghar Jarrahpour, Edris Ebrahimi, Malihe Aye, Seid Ali Torabi BadrabadyAbstract:A modified traditional preparative chromatographic column can be used to achieve quantitative N-Dearylation of N-(alkoxyphenyl), N-(alkoxynaphthyl), and N-(alkoxybenzyl)-2-azetidinones under mild conditions. Starting materials are charged on top of the column and the pure N-unsubstituted 2-azetidinones leave the column minutes later without need for other purifications. The yields are good-to-excellent and the reaction condition is mild, easy, efficient, and cheap.
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Argentic Oxide Mediated N-Dearylation of β-Lactams.
ChemInform, 2011Co-Authors: Maaroof Zarei, Aliasghar JarrahpourAbstract:The use of AgO allows a simple and efficient process which affords, compared to CAN, similar yields within a shorter time (10 min versus 45 min).
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Argentic oxide mediated N-Dearylation of β-lactams
Tetrahedron Letters, 2011Co-Authors: Maaroof Zarei, Aliasghar JarrahpourAbstract:Abstract A method is described for the N-Dearylation of N -(4-methoxy- or 4-ethoxyphenyl)-2-azetidinones with argentic oxide. The yields are good-to-excellent and the reaction is simple, efficient, and fast.
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Synthesis of N-unsubstituted β-lactams from N-alkoxyphenyl-β-lactams with cobalt(III) fluoride
Tetrahedron Letters, 2010Co-Authors: Maaroof Zarei, Aliasghar JarrahpourAbstract:Mild and efficient oxidative N-Dearylation of N-alkoxyphenyl-β-lactams with cobalt(III) fluoride proceeded in good to excellent yields to afford the corresponding N-unsubstituted β-lactams. Optimization of the solvent, molar ratio of reagents, time, and temperature are described.
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Ceric Ammonium Nitrate on Silica Gel for Solid–Solid Phase N-Dearylation of β -Lactams
Phosphorus Sulfur and Silicon and the Related Elements, 2009Co-Authors: Aliasghar Jarrahpour, Maaroof ZareiAbstract:Silica gel–supported ceric ammonium nitrate (CAN-SiO 2 ) has been found to be an effective reagent for the solid–solid phase and solvent-free N-Dearylation of β-lactams. The results have been compared with CAN alone in solution and solid–solid phase.
Shunsuke Chiba - One of the best experts on this subject based on the ideXlab platform.
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Dearylation of arylphosphine oxides using a sodium hydride–iodide composite
Chemical communications (Cambridge England), 2018Co-Authors: Ciputra Tejo, Jia Hao Pang, Derek Yiren Ong, Masanobu Uchiyama, Ryo Takita, Shunsuke ChibaAbstract:A new protocol for the Dearylation of arylphosphine oxides was developed using sodium hydride (NaH) in the presence of lithium iodide (LiI). The transient sodium phosphinite could be functionalized with a range of electrophiles in a one-pot fashion.
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Dearylation of arylphosphine oxides using a sodium hydride iodide composite
Chemical Communications, 2018Co-Authors: Ciputra Tejo, Jia Hao Pang, Derek Yiren Ong, Masanobu Uchiyama, Ryo Takita, Shunsuke ChibaAbstract:A new protocol for the Dearylation of arylphosphine oxides was developed using sodium hydride (NaH) in the presence of lithium iodide (LiI). The transient sodium phosphinite could be functionalized with a range of electrophiles in a one-pot fashion.
Luke A. Burke - One of the best experts on this subject based on the ideXlab platform.
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A Ceric Ammonium Nitrate N-Dearylation of N-p-Anisylazoles Applied to Pyrazole, Triazole, Tetrazole, and Pentazole Rings: Release of Parent Azoles. Generation of Unstable Pentazole, HN5/N5-, in Solution
The Journal of organic chemistry, 2008Co-Authors: Richard N. Butler, John M. Hanniffy, John C. Stephens, Luke A. BurkeAbstract:The reaction of cerium(IV) ammonium nitrate (CAN) with a range of N-(p-anisyl)azoles in acetonitrile or methanol solvents leads to N-Dearylation releasing the parent NH-azole and p-benzoquinone in comparable yields. The scope and limitations of the reaction are explored. It was successful with 1-(p-anisyl)pyrazoles, 2-(p-anisyl)-1,2,3-triazoles, 2-(p-anisyl)-2H-tetrazoles, and 1-(p-anisyl)pentazole. The Dearylation renders the p-anisyl group as a potentially useful N-protecting group in azole chemistry. The azole released in solution from 1-(p-anisyl)pentazole is unstable HN5, the long-sought parent pentazolic acid. p-Anisylpentazole samples were synthesized with combinations of one, two, and three 15N atoms at all positions of the pentazole ring. The unstable HN5/N5- produced at −40 °C did not build up in the solution but degraded to azide ion and nitrogen gas with a short lifetime. The 15N-labeling of the N3- ion obtained from all samples proved unequivocally that it came from the degradation of HN5 (ta...
D. Donghi - One of the best experts on this subject based on the ideXlab platform.
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19f nmr spectroscopic investigation of the reaction of bis pentafluorophenyl borinic acid with a proton sponge deprotonation trimerization and stepwise Dearylation
European Journal of Inorganic Chemistry, 2008Co-Authors: D. Donghi, D. Maggioni, T. Beringhelli, Giuseppe DalfonsoAbstract:The reaction of Ar2BOH (1, Ar = C6F5) with the proton sponge bis(dimethylamino)naphthalene (DMAN) in CD2Cl2 solution caused a series of strictly interlaced processes that have been investigated by variable-temperature 1H and 19F NMR spectroscopy. The very slow equilibrium between the monomeric and cyclic trimeric forms of Ar2BOH was strongly accelerated by the presence of a catalytic amount of DMAN. Upon addition of stoichiometric DMAN (0.33 equiv.), all Ar2BOH was converted into a mixture of two boroxinate anions, namely [Ar6B3O3H2]– (2) and [Ar5B3O3H]– (3), in which the ratio of the two anions varied according to the reaction conditions. The formation of the dearylated anion 3 (accompanied by equimolar pentafluorobenzene) has been attributed to a reaction process parallel to that leading to the hexaaryl anion 2, involving base-catalyzed hydrolysis of monomeric perfluoroborinic acid to its boronic analogue, followed by aggregation and condensation. Water plays a catalytic role in this process. In the presence of a small excess of DMAN, complete and instantaneous Dearylation of 2 to 3 was observed. At temperatures lower than 233 K, the pentaaryl anion 3 was in equilibrium with its conjugate base. Slow further Dearylation occurred at temperatures higher than 263 K, cleanly affording the tetraaryl anion [Ar4B3O3]– (5). Anions 3 and 5 have also been obtained in high yields from the condensation reaction between Ar2BOH and ArB(OH)2 (in the ratio 2:1 and 1:2, respectively), in the presence of stoichiometric DMAN. Mechanisms responsible for the stepwise Dearylation from 2 to 3 and then from 3 to 5 have been discussed.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
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19F NMR investigation of the reaction of bis(pentafluorophenyl)borinic acid with a "proton sponge" : deprotonation, trimerization and stepwise Dearylation
'Wiley', 2008Co-Authors: D. Donghi, D. Maggioni, T. Beringhelli, G. D’Abstract:The reaction of Ar2BOH (1, Ar = C6F5) with the proton sponge bis(dimethylamino)naphthalene (DMAN) in CD2Cl2 solution caused a series of strictly interlaced processes, that have been investigated by variable temperature 1H and 19F NMR spectroscopy. The very slow equilibrium between the monomeric and cyclic trimeric forms of Ar2BOH was strongly accelerated by the presence of a catalytic amount of DMAN. Upon addition of stoichiometric DMAN (0.33 equivalents), all Ar2BOH was converted into a mixture of two boroxinate anions, namely [Ar6B3O3H2]\u2013 (2) and [Ar5B3O3H]\u2013 (3), in different ratios on varying the reaction conditions. The formation of the dearylated anion 3 (accompanied by equimolar pentafluorobenzene) has been attributed to a reaction process parallel to that leading to the hexa-aryl anion 2, involving base-catalyzed hydrolysis of monomeric perfluoroborinic acid to its boronic analogue, followed by aggregation and condensation. Water plays a catalytic role in this process. In the presence of a small excess of DMAN, complete and instantaneous Dearylation of 2 to 3 was observed. At temperatures lower than 233 K, the penta-aryl anion 3 was in equilibrium with its conjugate base. Slow further Dearylation occurred at temperatures higher than 263 K, cleanly affording the tetra-aryl anion [Ar4B3O3]\u2013 (5). Both anions 3 and 5 have been obtained in high yields also from the condensation of Ar2BOH and ArB(OH)2 (in the ratio 2:1 or 1:2, respectively), in the presence of stoichiometric DMAN. Mechanisms responsible for the stepwise Dearylation from 2 to 3 and then from 3 to 5 have been discussed
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19F NMR Spectroscopic Investigation of the Reaction of Bis(pentafluorophenyl)borinic Acid with a “Proton Sponge”: Deprotonation, Trimerization and Stepwise Dearylation
European Journal of Inorganic Chemistry, 2008Co-Authors: D. Donghi, D. Maggioni, T. Beringhelli, Giuseppe D'alfonsoAbstract:The reaction of Ar2BOH (1, Ar = C6F5) with the proton sponge bis(dimethylamino)naphthalene (DMAN) in CD2Cl2 solution caused a series of strictly interlaced processes that have been investigated by variable-temperature 1H and 19F NMR spectroscopy. The very slow equilibrium between the monomeric and cyclic trimeric forms of Ar2BOH was strongly accelerated by the presence of a catalytic amount of DMAN. Upon addition of stoichiometric DMAN (0.33 equiv.), all Ar2BOH was converted into a mixture of two boroxinate anions, namely [Ar6B3O3H2]– (2) and [Ar5B3O3H]– (3), in which the ratio of the two anions varied according to the reaction conditions. The formation of the dearylated anion 3 (accompanied by equimolar pentafluorobenzene) has been attributed to a reaction process parallel to that leading to the hexaaryl anion 2, involving base-catalyzed hydrolysis of monomeric perfluoroborinic acid to its boronic analogue, followed by aggregation and condensation. Water plays a catalytic role in this process. In the presence of a small excess of DMAN, complete and instantaneous Dearylation of 2 to 3 was observed. At temperatures lower than 233 K, the pentaaryl anion 3 was in equilibrium with its conjugate base. Slow further Dearylation occurred at temperatures higher than 263 K, cleanly affording the tetraaryl anion [Ar4B3O3]– (5). Anions 3 and 5 have also been obtained in high yields from the condensation reaction between Ar2BOH and ArB(OH)2 (in the ratio 2:1 and 1:2, respectively), in the presence of stoichiometric DMAN. Mechanisms responsible for the stepwise Dearylation from 2 to 3 and then from 3 to 5 have been discussed.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
