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Brandon Q Mercado - One of the best experts on this subject based on the ideXlab platform.
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, ...
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents.
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Controlling the Conformational Energy of a Phenyl Group by Tuning the Strength of a Nonclassical CH···O Hydrogen Bond: The Case of 5‑Phenyl-1,3-dioxane
2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents
William F Bailey - One of the best experts on this subject based on the ideXlab platform.
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, ...
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents.
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Controlling the Conformational Energy of a Phenyl Group by Tuning the Strength of a Nonclassical CH···O Hydrogen Bond: The Case of 5‑Phenyl-1,3-dioxane
2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents
Tsuyosi Anraku - One of the best experts on this subject based on the ideXlab platform.
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design and synthesis of novel 7 heterocycle 6 trifluoromethyl 3 oxoquinoxaline 2 carboxylic acids bearing a substituted Phenyl Group as superior ampa receptor antagonists with good physicochemical properties
Bioorganic & Medicinal Chemistry, 2006Co-Authors: Yasuo Takano, Futoshi Shiga, Jun Asano, Wataru Hori, Kazunori Fukuchi, Tsuyosi AnrakuAbstract:Abstract We describe the design, synthesis, and physicochemical and biological properties of a novel series of 7-heterocycle-6-trifluoromethyl-3-oxoquinoxaline-2-carboxylic acids bearing a substituted Phenyl Group joined through a urethane or urea linkage to the heterocycle at the 7 position. Introduction of the trifluoromethyl Group at the 6 position conferred good biological activity, including neuroprotective effects, as well as good physicochemical properties. In terms of α-amino-3-hydroxy-5-methylisoxazole propionate receptor (AMPA-R) affinity, a urea linkage was equivalent to a urethane linkage and a pyrrole ring at the 7 position reduced affinity in comparison with an imidazole ring. Among this series, compound 14h ( KRP - 199 ), which has a 4-carboxyPhenyl Group joined through a urethane linkage to a 7-imidazolyl heterocycle, was found to possess high potency and selectivity for the AMPA-R in vitro and to exhibit good neuroprotective effects in vivo. Furthermore, the compound showed good physicochemical properties, including stability to light and good solubility in aqueous solutions.
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synthesis and ampa receptor antagonistic activity of a novel 7 imidazolyl 6 trifluoromethyl quinoxalinecarboxylic acid with a substituted Phenyl Group and improved its good physicochemical properties by introduced cf3 Group
Bioorganic & Medicinal Chemistry Letters, 2004Co-Authors: Yasuo Takano, Futoshi Shiga, Jun Asano, Wataru Hori, Tsuyosi Anraku, Takashi UnoAbstract:We describe the synthesis, physicochemical, and biological properties of a novel series of 7-imidazolyl-6-trifluoromethyl quinoxalinecarboxylic acids with a substituted Phenyl Group attached through a urethane linkage at the C-7 position. We found that the introduction of trifluoromethyl Group at the C-6 position brought about good biological activity and physicochemical properties. Among them, compound 9k (KRP-199), which has a 4-carboxyPhenyl Group, was found to possess high potency and selectivity for the AMPA-R in vitro and to exhibit good neuroprotective effects in vivo. Furthermore, the compound showed good physicochemical properties such as stability to light and good solubility in aqueous solutions.
Kenneth B Wiberg - One of the best experts on this subject based on the ideXlab platform.
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, ...
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents.
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Controlling the Conformational Energy of a Phenyl Group by Tuning the Strength of a Nonclassical CH···O Hydrogen Bond: The Case of 5‑Phenyl-1,3-dioxane
2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents
Zachary D Stempel - One of the best experts on this subject based on the ideXlab platform.
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, ...
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controlling the conformational energy of a Phenyl Group by tuning the strength of a nonclassical ch o hydrogen bond the case of 5 Phenyl 1 3 dioxane
Journal of Organic Chemistry, 2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents.
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Controlling the Conformational Energy of a Phenyl Group by Tuning the Strength of a Nonclassical CH···O Hydrogen Bond: The Case of 5‑Phenyl-1,3-dioxane
2016Co-Authors: William F Bailey, Kyle M Lambert, Zachary D Stempel, Kenneth B Wiberg, Brandon Q MercadoAbstract:Anancomeric 5-Phenyl-1,3-dioxanes provide a unique opportunity to study factors that control conformation. Whereas one might expect an axial Phenyl Group at C(5) of 1,3-dioxane to adopt a conformation similar to that in axial Phenylcyclohexane, a series of studies including X-ray crystallography, NOE measurements, and DFT calculations demonstrate that the Phenyl prefers to lie over the dioxane ring in order to position an ortho-hydrogen to participate in a stabilizing, nonclassical CH···O hydrogen bond with a ring oxygen of the dioxane. Acid-catalyzed equilibration of a series of anancomeric 2-tert-butyl-5-aryl-1,3-dioxane isomers demonstrates that remote substituents on the Phenyl ring affect the conformational energy of a 5-aryl-1,3-dioxane: electron-withdrawing substituents decrease the conformational energy of the aryl Group, while electron-donating substituents increase the conformational energy of the Group. This effect is correlated in a very linear way to Hammett substituent parameters. In short, the strength of the CH···O hydrogen bond may be tuned in a predictable way in response to the electron-withdrawing or electron-donating ability of substituents positioned remotely on the aryl ring. This effect may be profound: a 3,5-bis-CF3 Phenyl Group at C(5) in 1,3-dioxane displays a pronounced preference for the axial orientation. The results are relevant to broader conformational issues involving heterocyclic systems bearing aryl substituents
