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Hyunik Shin - One of the best experts on this subject based on the ideXlab platform.
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Tandem Transformations of Nitriles into N-Heterocyclic Compounds by Electrophilic Trapping of Blaise Reaction Intermediates
Synthesis, 2012Co-Authors: Yu Sung Chun, Hyunik ShinAbstract:Tandem transformations of nitriles into various N-heterocycles have been accomplished through the Reaction of electrophiles with Blaise Reaction Intermediates formed in situ. The Reaction of the Blaise Reaction Intermediates with propiolates gives 2-pyridones through consecutive C- and N-nucleophilic Reactions. The tandem Reactions of the Blaise Reaction Intermediate with 1,3-enynes proceed through C-nucleophilic addition followed by an electrocyclization–aromatization cascade to give pyridines. Exocyclic enamino esters can be prepared by transformations of ω-chloroalkyl nitriles through chemoselective intramolecular alkylation of the Blaise Reaction Intermediate. Palladium-catalyzed intramolecular arylations or copper-catalyzed intermolecular cross-coupling Reactions of the Blaise Reaction Intermediate give a range of indole derivatives. Combinations of tandem alkylations and palladium-catalyzed couplings of the Blaise Reaction Intermediates of ω-chloroalkyl nitriles give N-fused indoles.
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tandem one pot synthesis of α aminomethylene γ butyrolactones via regioselective epoxide ring opening with the blaise Reaction Intermediate
ChemInform, 2011Co-Authors: Young Ok Ko, Yu Sung Chun, Hyunik ShinAbstract:The Reaction of the Reformatsky reagent derived from ethyl bromoacetate and subsequent coupling of the resulting Blaise Intermediate with oxiranes allows the synthesis of the title compounds in fair yields.
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tandem one pot synthesis of α aminomethylene γ butyrolactones via regioselective epoxide ring opening with the blaise Reaction Intermediate
Tetrahedron Letters, 2010Co-Authors: Young Ok Ko, Yu Sung Chun, Hyunik ShinAbstract:A novel tandem one-pot method for the synthesis of α-aminomethylene-γ-butyrolactone derivatives has been developed through the regioselective epoxide opening Reactions with the Blaise Reaction Intermediates, generated by the Reaction of a Reformatsky reagent with nitriles. Formation of a modified Blaise Reaction Intermediate by the addition of a stoichiometric amount of n-BuLi followed by slow addition of epoxide is required for the good yield of γ-butyrolactones.
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the first chemoselective tandem acylation of the blaise Reaction Intermediate a novel method for the synthesis of α acyl β enamino esters key Intermediate for pyrazoles
Chemical Communications, 2008Co-Authors: Yu Sung Chun, Young Ok Ko, Hyunik ShinAbstract:The Blaise Reaction Intermediate, a zinc bromide complex of β-enamino ester, could be activated in situ by addition of a stoichiometric or catalytic amount of n-BuLi to allow chemoselective tandem C2-acylation providing α-acyl-β-enamino esters, which are valuable Intermediates for the syntheses of tri- and tetrasubstituted pyrazoles.
Yu Sung Chun - One of the best experts on this subject based on the ideXlab platform.
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an expedient and divergent tandem one pot synthesis of pyrimidin 2 4 diones using the blaise Reaction Intermediate
Organic Letters, 2013Co-Authors: Yu Sung Chun, Zi XuanAbstract:A novel divergent tandem one-pot method for the synthesis of 3,5,6-trisubstituted 1H-pyrimidin-2,4-dione derivatives is developed. In the presence of 10 mol % of Cu(OAc)2, the α-substituted Blaise Reaction Intermediates (R2 ≠ H) reacted with isocyanates chemoselectively to afford pyrimidin-2,4-diones, whereas the α-unsubstituted Blaise Reaction Intermediate (R2 = H) showed a propensity to be a C-nucleophile toward electrophiles, permitting the installation of different functionalities at the 5-position through sequential tandem Reactions.
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Tandem Transformations of Nitriles into N-Heterocyclic Compounds by Electrophilic Trapping of Blaise Reaction Intermediates
Synthesis, 2012Co-Authors: Yu Sung Chun, Hyunik ShinAbstract:Tandem transformations of nitriles into various N-heterocycles have been accomplished through the Reaction of electrophiles with Blaise Reaction Intermediates formed in situ. The Reaction of the Blaise Reaction Intermediates with propiolates gives 2-pyridones through consecutive C- and N-nucleophilic Reactions. The tandem Reactions of the Blaise Reaction Intermediate with 1,3-enynes proceed through C-nucleophilic addition followed by an electrocyclization–aromatization cascade to give pyridines. Exocyclic enamino esters can be prepared by transformations of ω-chloroalkyl nitriles through chemoselective intramolecular alkylation of the Blaise Reaction Intermediate. Palladium-catalyzed intramolecular arylations or copper-catalyzed intermolecular cross-coupling Reactions of the Blaise Reaction Intermediate give a range of indole derivatives. Combinations of tandem alkylations and palladium-catalyzed couplings of the Blaise Reaction Intermediates of ω-chloroalkyl nitriles give N-fused indoles.
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tandem one pot synthesis of polysubstituted pyridines using the blaise Reaction Intermediate and 1 3 enynes
ChemInform, 2012Co-Authors: Yu Sung Chun, Young Ok KoAbstract:Sequential Reaction of nitriles, Reformatsky reagents and 1,3-enynes proceeds with complete regio- and chemoselectivity to provide the polysubstituted pyridines.
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tandem one pot synthesis of polysubstituted pyridines using the blaise Reaction Intermediate and 1 3 enynes
Organic Letters, 2011Co-Authors: Yu Sung Chun, Young Ok KoAbstract:A tandem one-pot method for the construction of a pyridine moiety with selective control of substitution patterns has been developed through the sequential Reactions of nitrile with a Reformatsky reagent and 1,3-enyne involving regio- and chemoselective addition of the Blaise Reaction Intermediate to 1,3-enyne, followed by isomerization, cyclization, and an aromatization cascade.
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tandem one pot synthesis of α aminomethylene γ butyrolactones via regioselective epoxide ring opening with the blaise Reaction Intermediate
ChemInform, 2011Co-Authors: Young Ok Ko, Yu Sung Chun, Hyunik ShinAbstract:The Reaction of the Reformatsky reagent derived from ethyl bromoacetate and subsequent coupling of the resulting Blaise Intermediate with oxiranes allows the synthesis of the title compounds in fair yields.
Young Ok Ko - One of the best experts on this subject based on the ideXlab platform.
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tandem one pot synthesis of polysubstituted pyridines using the blaise Reaction Intermediate and 1 3 enynes
ChemInform, 2012Co-Authors: Yu Sung Chun, Young Ok KoAbstract:Sequential Reaction of nitriles, Reformatsky reagents and 1,3-enynes proceeds with complete regio- and chemoselectivity to provide the polysubstituted pyridines.
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tandem one pot synthesis of polysubstituted pyridines using the blaise Reaction Intermediate and 1 3 enynes
Organic Letters, 2011Co-Authors: Yu Sung Chun, Young Ok KoAbstract:A tandem one-pot method for the construction of a pyridine moiety with selective control of substitution patterns has been developed through the sequential Reactions of nitrile with a Reformatsky reagent and 1,3-enyne involving regio- and chemoselective addition of the Blaise Reaction Intermediate to 1,3-enyne, followed by isomerization, cyclization, and an aromatization cascade.
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tandem one pot synthesis of α aminomethylene γ butyrolactones via regioselective epoxide ring opening with the blaise Reaction Intermediate
ChemInform, 2011Co-Authors: Young Ok Ko, Yu Sung Chun, Hyunik ShinAbstract:The Reaction of the Reformatsky reagent derived from ethyl bromoacetate and subsequent coupling of the resulting Blaise Intermediate with oxiranes allows the synthesis of the title compounds in fair yields.
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tandem one pot synthesis of α aminomethylene γ butyrolactones via regioselective epoxide ring opening with the blaise Reaction Intermediate
Tetrahedron Letters, 2010Co-Authors: Young Ok Ko, Yu Sung Chun, Hyunik ShinAbstract:A novel tandem one-pot method for the synthesis of α-aminomethylene-γ-butyrolactone derivatives has been developed through the regioselective epoxide opening Reactions with the Blaise Reaction Intermediates, generated by the Reaction of a Reformatsky reagent with nitriles. Formation of a modified Blaise Reaction Intermediate by the addition of a stoichiometric amount of n-BuLi followed by slow addition of epoxide is required for the good yield of γ-butyrolactones.
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the first chemoselective tandem acylation of the blaise Reaction Intermediate a novel method for the synthesis of α acyl β enamino esters key Intermediate for pyrazoles
Chemical Communications, 2008Co-Authors: Yu Sung Chun, Young Ok Ko, Hyunik ShinAbstract:The Blaise Reaction Intermediate, a zinc bromide complex of β-enamino ester, could be activated in situ by addition of a stoichiometric or catalytic amount of n-BuLi to allow chemoselective tandem C2-acylation providing α-acyl-β-enamino esters, which are valuable Intermediates for the syntheses of tri- and tetrasubstituted pyrazoles.
Douglas W Stephan - One of the best experts on this subject based on the ideXlab platform.
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flp reactivity of ph3c and o tolyl 3p and the capture of a staudinger Reaction Intermediate
Dalton Transactions, 2017Co-Authors: Jiliang Zhou, Douglas W StephanAbstract:The frustrated Lewis pair (FLP) derived from the trityl cation and (o-tolyl)3P effects the activation of 1,4-cyclohexadiene and 1-bromo-4-ethynylbenzene and heterolytically cleaves the S–S bond of diphenyl disulfide. The FLP also captures pentafluorophenyl azide as the Staudinger Reaction Intermediate, a species that reacts with Ph3SiH to give the silyl analog.
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FLP reactivity of [Ph3C]+ and (o-tolyl)3P and the capture of a Staudinger Reaction Intermediate
Dalton Transactions, 2017Co-Authors: Jiliang Zhou, Douglas W StephanAbstract:The frustrated Lewis pair (FLP) derived from the trityl cation and (o-tolyl)3P effects the activation of 1,4-cyclohexadiene and 1-bromo-4-ethynylbenzene and heterolytically cleaves the S–S bond of diphenyl disulfide. The FLP also captures pentafluorophenyl azide as the Staudinger Reaction Intermediate, a species that reacts with Ph3SiH to give the silyl analog.
C. C. Query - One of the best experts on this subject based on the ideXlab platform.
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repositioning of the Reaction Intermediate within the catalytic center of the spliceosome
Molecular Cell, 2006Co-Authors: Maria M. Konarska, J Vilardell, C. C. QueryAbstract:Summary Conformational change within the spliceosome is required between the first catalytic step of pre-mRNA splicing, when the branch site attacks the 5′ splice site (SS), and the second step, when the 5′ exon attacks the 3′SS. Little is known, however, about repositioning of the Reaction substrates during this transition. Whereas the 5′SS is positioned for the first step by pairing with the invariant U6 snRNA-ACAGAG site, we demonstrate that this pairing interaction must be disrupted to allow transition to the second step. We propose that removal of the branch structure from the catalytic center is in competition with binding of the 3′SS substrate for the second step. Changes in the relative occupancy of first and second step substrates at the catalytic center alter efficiency of the two steps of splicing, allowing use of suboptimal intron sequences and thereby altering substrate selectivity.
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Repositioning of the Reaction Intermediate within the catalytic center of the spliceosome
Molecular Cell, 2006Co-Authors: Maria M. Konarska, J Vilardell, C. C. QueryAbstract:Conformational change within the spliceosome is required between the first catalytic step of pre-mRNA splicing, when the branch site attacks the 5′ splice site (SS), and the second step, when the 5′ exon attacks the 3′SS. Little is known, however, about repositioning of the Reaction substrates during this transition. Whereas the 5′SS is positioned for the first step by pairing with the invariant U6 snRNA-ACAGAG site, we demonstrate that this pairing interaction must be disrupted to allow transition to the second step. We propose that removal of the branch structure from the catalytic center is in competition with binding of the 3′SS substrate for the second step. Changes in the relative occupancy of first and second step substrates at the catalytic center alter efficiency of the two steps of splicing, allowing use of suboptimal intron sequences and thereby altering substrate selectivity. ©2006 Elsevier Inc.
