The Experts below are selected from a list of 1290 Experts worldwide ranked by ideXlab platform
Jose M Lassaletta - One of the best experts on this subject based on the ideXlab platform.
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synthesis of enantioenriched azo compounds organocatalytic michael addition of formaldehyde n tert butyl hydrazone to nitroalkenes
ChemInform, 2013Co-Authors: David Monge, Silvia Daza, Pablo Bernal, Rosario Fernandez, Jose M LassalettaAbstract:The asymmetric Michael addition of hydrazone (I) to nitroalkenes (II) leads to Diazenes (III), which are readily converted into tautomeric hydrazones (IV) under the action of TFA.
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synthesis of enantioenriched azo compounds organocatalytic michael addition of formaldehyde n tert butyl hydrazone to nitroalkenes
Organic and Biomolecular Chemistry, 2013Co-Authors: David Monge, Silvia Daza, Pablo Bernal, Rosario Fernandez, Jose M LassalettaAbstract:The unprecedented diaza–ene reaction of formaldehyde N-tert-butyl hydrazone with nitroalkenes can be efficiently catalyzed by an axially chiral bis-thiourea to afford the corresponding Diazenes in good to excellent yields (60–96%) and moderate enantioselectivities, up to 84 : 16 er; additional transformation of Diazenes into their tautomeric hydrazones proved to be operationally simple and high-yielding, affording bifunctional compounds which represent useful intermediates for the synthesis of enantioenriched β-nitro-nitriles and derivatives thereof.
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asymmetric formal carbonyl ene reactions of formaldehyde tert butyl hydrazone with α keto esters dual activation by bis urea catalysts
Journal of the American Chemical Society, 2012Co-Authors: Ana Crespopena, David Monge, Rosario Fernandez, Eloisa Martinzamora, Eleuterio Alvarez, Jose M LassalettaAbstract:The dual activation of α-keto esters and formaldehyde tert-butyl hydrazone by BINAM-derived bis-ureas is the key to achieve high reactivity and excellent enantioselectivities in nucleophilic addition (formal carbonyl-ene reaction) to functionalized tertiary carbinols. Ensuing high-yielding Diazene-to-aldehyde tranformations and subsequent derivatizations provides a direct entry to a variety of densely functionalized products.
Liu-zhu Gong - One of the best experts on this subject based on the ideXlab platform.
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chiral gold complex catalyzed hetero diels alder reaction of Diazenes highly enantioselective and general for dienes
Journal of the American Chemical Society, 2013Co-Authors: Kangnan Li, Jianzhou Huang, Huan Pang, Liu-zhu GongAbstract:A chiral gold(I) complex-catalyzed highly regio- and enantioselective azo hetero-Diels–Alder reaction has been developed. The chiral gold(I) complex acting as a Lewis acid exhibits high efficiency in the activation of urea-based Diazene dienophiles. Moreover, this chiral gold catalyst also rendered a cascade intramolecular enyne cycloisomerization/asymmetric azo-HDA reaction.
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Chiral Gold Complex-Catalyzed Hetero-Diels–Alder Reaction of Diazenes: Highly Enantioselective and General for Dienes
2013Co-Authors: Bin Liu, Jianzhou Huang, Huan Pang, Shi-wei Luo, Liu-zhu GongAbstract:A chiral gold(I) complex-catalyzed highly regio- and enantioselective azo hetero-Diels–Alder reaction has been developed. The chiral gold(I) complex acting as a Lewis acid exhibits high efficiency in the activation of urea-based Diazene dienophiles. Moreover, this chiral gold catalyst also rendered a cascade intramolecular enyne cycloisomerization/asymmetric azo-HDA reaction
David Monge - One of the best experts on this subject based on the ideXlab platform.
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synthesis of enantioenriched azo compounds organocatalytic michael addition of formaldehyde n tert butyl hydrazone to nitroalkenes
ChemInform, 2013Co-Authors: David Monge, Silvia Daza, Pablo Bernal, Rosario Fernandez, Jose M LassalettaAbstract:The asymmetric Michael addition of hydrazone (I) to nitroalkenes (II) leads to Diazenes (III), which are readily converted into tautomeric hydrazones (IV) under the action of TFA.
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synthesis of enantioenriched azo compounds organocatalytic michael addition of formaldehyde n tert butyl hydrazone to nitroalkenes
Organic and Biomolecular Chemistry, 2013Co-Authors: David Monge, Silvia Daza, Pablo Bernal, Rosario Fernandez, Jose M LassalettaAbstract:The unprecedented diaza–ene reaction of formaldehyde N-tert-butyl hydrazone with nitroalkenes can be efficiently catalyzed by an axially chiral bis-thiourea to afford the corresponding Diazenes in good to excellent yields (60–96%) and moderate enantioselectivities, up to 84 : 16 er; additional transformation of Diazenes into their tautomeric hydrazones proved to be operationally simple and high-yielding, affording bifunctional compounds which represent useful intermediates for the synthesis of enantioenriched β-nitro-nitriles and derivatives thereof.
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asymmetric formal carbonyl ene reactions of formaldehyde tert butyl hydrazone with α keto esters dual activation by bis urea catalysts
Journal of the American Chemical Society, 2012Co-Authors: Ana Crespopena, David Monge, Rosario Fernandez, Eloisa Martinzamora, Eleuterio Alvarez, Jose M LassalettaAbstract:The dual activation of α-keto esters and formaldehyde tert-butyl hydrazone by BINAM-derived bis-ureas is the key to achieve high reactivity and excellent enantioselectivities in nucleophilic addition (formal carbonyl-ene reaction) to functionalized tertiary carbinols. Ensuing high-yielding Diazene-to-aldehyde tranformations and subsequent derivatizations provides a direct entry to a variety of densely functionalized products.
Ajit J Thakkar - One of the best experts on this subject based on the ideXlab platform.
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dipole oscillator strength distributions sum rules mean excitation energies and isotropic van der waals coefficients for benzene pyridazine pyrimidine pyrazine s triazine toluene hexafluorobenzene and nitrobenzene
Journal of Chemical Physics, 2020Co-Authors: Ajit J ThakkarAbstract:Experimental, theoretical, and additive-model photoabsorption cross sections combined with constraints provided by the Kuhn-Reiche-Thomas sum rule and the high-energy behavior of the dipole oscillator strength density are used to construct dipole oscillator strength distributions for benzene, pyridazine (1,2-diazine), pyrimidine (1,3-diazine), pyrazine (1,4-diazine), s-triazine (1,3,5-triazine), toluene (methylbenzene), hexafluorobenzene, and nitrobenzene. The distributions are used to predict dipole sum rules S(k) for -6 ≤ k ≤ 2, mean excitation energies I(k) for -2 ≤ k ≤ 2, and isotropic van der Waals C6 coefficients. A popular combination rule for estimating C6 coefficients for unlike interactions from the C6 coefficients of the like interactions is found to be accurate to better than 1% for 606 of 628 cases (96.4%) in the test set.
Rosario Fernandez - One of the best experts on this subject based on the ideXlab platform.
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synthesis of enantioenriched azo compounds organocatalytic michael addition of formaldehyde n tert butyl hydrazone to nitroalkenes
ChemInform, 2013Co-Authors: David Monge, Silvia Daza, Pablo Bernal, Rosario Fernandez, Jose M LassalettaAbstract:The asymmetric Michael addition of hydrazone (I) to nitroalkenes (II) leads to Diazenes (III), which are readily converted into tautomeric hydrazones (IV) under the action of TFA.
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synthesis of enantioenriched azo compounds organocatalytic michael addition of formaldehyde n tert butyl hydrazone to nitroalkenes
Organic and Biomolecular Chemistry, 2013Co-Authors: David Monge, Silvia Daza, Pablo Bernal, Rosario Fernandez, Jose M LassalettaAbstract:The unprecedented diaza–ene reaction of formaldehyde N-tert-butyl hydrazone with nitroalkenes can be efficiently catalyzed by an axially chiral bis-thiourea to afford the corresponding Diazenes in good to excellent yields (60–96%) and moderate enantioselectivities, up to 84 : 16 er; additional transformation of Diazenes into their tautomeric hydrazones proved to be operationally simple and high-yielding, affording bifunctional compounds which represent useful intermediates for the synthesis of enantioenriched β-nitro-nitriles and derivatives thereof.
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asymmetric formal carbonyl ene reactions of formaldehyde tert butyl hydrazone with α keto esters dual activation by bis urea catalysts
Journal of the American Chemical Society, 2012Co-Authors: Ana Crespopena, David Monge, Rosario Fernandez, Eloisa Martinzamora, Eleuterio Alvarez, Jose M LassalettaAbstract:The dual activation of α-keto esters and formaldehyde tert-butyl hydrazone by BINAM-derived bis-ureas is the key to achieve high reactivity and excellent enantioselectivities in nucleophilic addition (formal carbonyl-ene reaction) to functionalized tertiary carbinols. Ensuing high-yielding Diazene-to-aldehyde tranformations and subsequent derivatizations provides a direct entry to a variety of densely functionalized products.