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Yoann Coquerel - One of the best experts on this subject based on the ideXlab platform.
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a stable n heterocyclic carbene organocatalyst for hydrogen deuterium exchange reactions between pseudoacids and Deuterated Chloroform
Journal of Organic Chemistry, 2015Co-Authors: Fabien Perez, Yajun Ren, Thomas Boddaert, Jean Rodriguez, Yoann CoquerelAbstract:It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/deuterium exchange reactions between pseudoacids and Chloroform-d1, while the analogous saturated NHC 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, the so-called SIMes, is inefficient for the same transformation. Experimental and computational DFT studies allowed these differences of reactivity to be attributed to the relative stability of the corresponding azolium–trichloromethyl anion ion pairs: in the former case, the complex evolves toward dissociation of the ions to produce an aromatic azolium cation and a basic trichloromethyl anion, while in the latter case, it evolves by ion recombination to give the product of formal carbene C–H insertion into the C–H bond of Chloroform. These results provide a rationale for some early intuitions and observations of Wanzlick, Arduengo, and others on the reactivity of NHCs with Chloroform as well as a simple organocatalytic method for the deuteration of pseudoacids (pKa,DMSO = 14–19) with Chloroform-d1.
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A Stable N-Heterocyclic Carbene Organocatalyst for Hydrogen/Deuterium Exchange Reactions between Pseudo-acids and Deuterated Chloroform
Journal of Organic Chemistry, 2015Co-Authors: Fabien Perez, Yajun Ren, Thomas Boddaert, Jean Rodriguez, Yoann CoquerelAbstract:It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropyl- phenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/ deuterium exchange reactions between pseudoacids and Chloroform- d1, while the analogous saturated NHC 1,3-bis(2,4,6-trimethyl- phenyl)imidazolin-2-ylidene, the so-called SIMes, is inefficient for the same transformation. Experimental and computational DFT studies allowed these differences of reactivity to be attributed to the relative stability of the corresponding azolium−trichloromethyl anion ion pairs: in the former case, the complex evolves toward dissociation of the ions to produce an aromatic azolium cation and a basic trichloromethyl anion, while in the latter case, it evolves by ion recombination to give the product of formal carbene C−H insertion into the C−H bond of Chloroform. These results provide a rationale for some early intuitions and observations of Wanzlick, Arduengo, and others on the reactivity of NHCs with Chloroform as well as a simple organocatalytic method for the deuteration of pseudoacids (pKa,DMSO = 14−19) with Chloroform-d1.
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A stable N-heterocyclic carbene organocatalyst for hydrogen/deuterium exchange reactions between pseudoacids and Deuterated Chloroform.
The Journal of Organic Chemistry, 2014Co-Authors: Fabien Perez, Yajun Ren, Thomas Boddaert, Jean Rodriguez, Yoann CoquerelAbstract:It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/deuterium exchange reactions between pseudoacids and Chloroform-d1, while the analogous saturated NHC 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, the so-called SIMes, is inefficient for the same transformation. Experimental and computational DFT studies allowed these differences of reactivity to be attributed to the relative stability of the corresponding azolium–trichloromethyl anion ion pairs: in the former case, the complex evolves toward dissociation of the ions to produce an aromatic azolium cation and a basic trichloromethyl anion, while in the latter case, it evolves by ion recombination to give the product of formal carbene C–H insertion into the C–H bond of Chloroform. These results provide a rationale for some early intuitions and observations of Wanzlick, Arduengo, and others on the reactivity of NHCs with Chloroform as well as a simple organocatalytic method for the deuteration of pseudoacids (pKa,DMSO = 14–19) with Chloroform-d1.
V A Sharnin - One of the best experts on this subject based on the ideXlab platform.
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inhibited rotation of amide group around cn bond of nicotinamide in different solvents by 1h nmr data
Journal of Molecular Liquids, 2017Co-Authors: G A Gamov, V V Aleksandriiskii, V A SharninAbstract:Abstract Present work reports on the influence of solvent nature on the intramolecular rotation barrier of nicotinamide amide group. The values of Gibbs energy of activation are determined at the coalescence temperature in Deuterated Chloroform, water, DMSO and aqueous dimethyl sulfoxide of variable composition. The rotation barrier in vacuum, Chloroform, DMSO and water is estimated by quantum chemistry methods and found to be in good agreement with experimental results. The energy profile of rotation process is shown to be asymmetrical due to lone pair inversion of amide nitrogen.
Andreas Hartwig - One of the best experts on this subject based on the ideXlab platform.
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Vibrational circular dichroism of 3-(trifluoroacetyl)-camphor and its interaction with chiral amines.
Chirality, 2010Co-Authors: Christian Merten, Karl J. Jalkanen, Volker C. Weiss, Andreas HartwigAbstract:Vibrational circular dichroism (VCD) spectroscopy and density functional theory (DFT) calculations are used to investigate the keto–enol equilibrium of 3-(trifluoroacetyl)-camphor (TFC) and to study the interaction of TFC with chiral amines in Deuterated Chloroform. It is shown that the VCD spectra of the enol- and keto forms of TFC can clearly be distinguished and that the enol form is favored. By deprotonation of the TFC enol with chiral amines, no indication of a mutual diasteriomeric influence on the VCD spectra induced by transfer of stereochemical information between the chiral ionic species is found, neither experimentally nor theoretically. Chirality 2010. © 2010 Wiley-Liss, Inc.
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Vibrational circular dichroism of 3-(trifluoroacetyl)-camphor and its interaction with chiral amines
Chirality, 2010Co-Authors: Christian Merten, Karl J. Jalkanen, Volker C. Weiss, Andreas HartwigAbstract:Vibrational circular dichroism (VCD) spectroscopy and density functional theory (DFT) calculations are used to investigate the keto-enol equilibrium of 3( trifluoroacetyl)-camphor (TFC) and to study the interaction of TFC with chiral amines in Deuterated Chloroform. It is shown that the VCD spectra of the enol-and keto forms of TFC can clearly be distinguished and that the enol form is favored. By deprotonation of the TFC enol with chiral amines, no indication of a mutual diasteriomeric influence on the VCD spectra induced by transfer of stereochemical information between the chiral ionic species is found, neither experimentally nor theoretically. Chirality 22: 772-777, 2010
Eitan Geva - One of the best experts on this subject based on the ideXlab platform.
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a mixed quantum classical molecular dynamics study of anti tetrol and syn tetrol dissolved in liquid Chloroform hydrogen bond structure and its signature on the infrared absorption spectrum
Journal of Physical Chemistry B, 2013Co-Authors: Kijeong Kwac, Eitan GevaAbstract:The intramolecular hydrogen-bond structure of stereoselectively synthesized syn-tetrol and anti-tetrol dissolved in Deuterated Chloroform is investigated via a mixed quantum-classical molecular dynamics simulation. An extensive conformational analysis is performed in order to determine the dominant conformations, the distributions among them, and their sensitivity to the method for assigning partial charges (RESP vs AM1-BCC). The signature of the conformational distribution and method of assigning partial charges on the infrared absorption spectra is analyzed in detail. The relationship between the spectra and the underlying hydrogen-bond structure is elucidated.
Fabien Perez - One of the best experts on this subject based on the ideXlab platform.
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a stable n heterocyclic carbene organocatalyst for hydrogen deuterium exchange reactions between pseudoacids and Deuterated Chloroform
Journal of Organic Chemistry, 2015Co-Authors: Fabien Perez, Yajun Ren, Thomas Boddaert, Jean Rodriguez, Yoann CoquerelAbstract:It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/deuterium exchange reactions between pseudoacids and Chloroform-d1, while the analogous saturated NHC 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, the so-called SIMes, is inefficient for the same transformation. Experimental and computational DFT studies allowed these differences of reactivity to be attributed to the relative stability of the corresponding azolium–trichloromethyl anion ion pairs: in the former case, the complex evolves toward dissociation of the ions to produce an aromatic azolium cation and a basic trichloromethyl anion, while in the latter case, it evolves by ion recombination to give the product of formal carbene C–H insertion into the C–H bond of Chloroform. These results provide a rationale for some early intuitions and observations of Wanzlick, Arduengo, and others on the reactivity of NHCs with Chloroform as well as a simple organocatalytic method for the deuteration of pseudoacids (pKa,DMSO = 14–19) with Chloroform-d1.
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A Stable N-Heterocyclic Carbene Organocatalyst for Hydrogen/Deuterium Exchange Reactions between Pseudo-acids and Deuterated Chloroform
Journal of Organic Chemistry, 2015Co-Authors: Fabien Perez, Yajun Ren, Thomas Boddaert, Jean Rodriguez, Yoann CoquerelAbstract:It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropyl- phenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/ deuterium exchange reactions between pseudoacids and Chloroform- d1, while the analogous saturated NHC 1,3-bis(2,4,6-trimethyl- phenyl)imidazolin-2-ylidene, the so-called SIMes, is inefficient for the same transformation. Experimental and computational DFT studies allowed these differences of reactivity to be attributed to the relative stability of the corresponding azolium−trichloromethyl anion ion pairs: in the former case, the complex evolves toward dissociation of the ions to produce an aromatic azolium cation and a basic trichloromethyl anion, while in the latter case, it evolves by ion recombination to give the product of formal carbene C−H insertion into the C−H bond of Chloroform. These results provide a rationale for some early intuitions and observations of Wanzlick, Arduengo, and others on the reactivity of NHCs with Chloroform as well as a simple organocatalytic method for the deuteration of pseudoacids (pKa,DMSO = 14−19) with Chloroform-d1.
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A stable N-heterocyclic carbene organocatalyst for hydrogen/deuterium exchange reactions between pseudoacids and Deuterated Chloroform.
The Journal of Organic Chemistry, 2014Co-Authors: Fabien Perez, Yajun Ren, Thomas Boddaert, Jean Rodriguez, Yoann CoquerelAbstract:It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/deuterium exchange reactions between pseudoacids and Chloroform-d1, while the analogous saturated NHC 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, the so-called SIMes, is inefficient for the same transformation. Experimental and computational DFT studies allowed these differences of reactivity to be attributed to the relative stability of the corresponding azolium–trichloromethyl anion ion pairs: in the former case, the complex evolves toward dissociation of the ions to produce an aromatic azolium cation and a basic trichloromethyl anion, while in the latter case, it evolves by ion recombination to give the product of formal carbene C–H insertion into the C–H bond of Chloroform. These results provide a rationale for some early intuitions and observations of Wanzlick, Arduengo, and others on the reactivity of NHCs with Chloroform as well as a simple organocatalytic method for the deuteration of pseudoacids (pKa,DMSO = 14–19) with Chloroform-d1.