Hydrogen Bonding in Nitro Compounds<sup>1</sup>

Ungnade, Herbert E.; Roberts, Elwyn; Kissinger, L. W.

doi:10.1021/j100793a024

Cited by 23 publications

(15 citation statements)

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“…2). A similar shift has been reported for the isotropic n-n* absorption of nitroalkanes in perfluoroalcohols (18). Although fluorinated solvents have large effects (9,19) and fluorine substituents are "antioctant" (20,21) iApproximate only due to strong isotropic absorption.…”

Section: Nitro Compoundssupporting

confidence: 78%

“…band of the system RNO2/5 upon addition of H F P may be attributed, and we conclude that the action of HFP is upon the system CIS rather than on either C or S alone. That the strong hydrogen-bonding properties of HFP (9) It is generally agreed that the nitro group can act as a proton acceptor for hydrogen bonding from alcohols (18,24,25). As the efficiency of H F P for hydrogen-bonding to proton acceptors is greater than that of methanol (9) sorbide (Table 4) The 330 nm band in the isotropic spectrum of nitrobenzene is usually attributed to a n-n* transition by analogy with nitroalkanes (16).…”

Section: Fig 2 Induced Circular Dichroism Of Nitromethane (051 M )mentioning

confidence: 99%

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Optical Activity of Symmetric Compounds in Chiral Media. I. Induced Circular Dichroism of Unbound Substrates

Hayward¹,

Totty²

1971

Can. J. Chem.

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In the presence of chiral environment compounds, C, optical rotation is induced in symmetric substrates, S, and may be detected as circular dichroism in the electronic spectra of the solutions. Thus the n-?I* transitions of symmetric and racemic carbonyl compounds, and of symmetric nitro and azo compounds, become optically active when these S are dissolved in chiral hydrocarbons, ketones, or carbinols, or in solutions of these C in achiral solvents. The rotational strengths of the induced circular dichroism bands of S are solvent, temperature, and concentration dependent. Only limited correlation of the sign and magnitude of the induced bands with the stereochemistry of C and S is evident on the data so far accumulated. Halogenated achiral solvents enhance the intensity, and, in some cases reverse the sign of the induced bands.A new mechanism of asymmetric induction is proposed in which specific bonding of C with S is not prerequisite.

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Section: Nitro Compoundssupporting

confidence: 78%

Section: Fig 2 Induced Circular Dichroism Of Nitromethane (051 M )mentioning

confidence: 99%

Optical Activity of Symmetric Compounds in Chiral Media. I. Induced Circular Dichroism of Unbound Substrates

Hayward¹,

Totty²

1971

Can. J. Chem.

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“…13,[32][33][34][35][36][37][38][39] This process is enabled by the nitro groups of EB that are good hydrogen-bond acceptors. [24][25][26]40,41 In order to further confirm this hypothesis, TA measurements were carried out in perdeuterated water. As expected for the hydrogen-bond assisted deactivation mechanism, the dynamics in D 2 O was slower than in H 2 O (Figure 10) by approximately a factor 1.5 (Table 2).…”

Section: Articlementioning

confidence: 99%

Ultrafast Excited-State Dynamics of Eosin B: A Potential Probe of the Hydrogen-Bonding Properties of the Environment

2011

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The photophysics of two dyes from the xanthene family, eosin B (EB), and eosin Y (EY) has been investigated in various solvents by femtosecond transient absorption spectroscopy, first, to clarify the huge disparity of the EB fluorescence lifetimes reported in literature, and, second, to understand the mechanism responsible for the ultrafast excited-state deactivation of EB in water. The excited-state lifetime of EB was found to be much shorter in water and in other protic solvents, due to the occurrence of hydrogen-bond assisted nonradiative deactivation. This mechanism is associated with the hydrogen bonds between the solvent molecules and the nitro groups of EB, which become stronger upon optical excitation due to the charge-transfer character of the excited-state. This process is not operative with EY, where the nitro groups are replaced by bromine atoms. Therefore, the excited-state lifetime of EB in solution is directly related to the strength of the solvent as a hydrogen-bond donor, offering the possibility to build a corresponding scale based on the fluorescence quantum yield or lifetime of EB. This scale of hydrogen-bonding strength could be especially useful for studies of liquid interfaces by time-resolved surface second harmonic generation

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“…On account of the fact that the nitro group generally functioned as a relatively weak H-bond acceptor in molecular interactions and has a relatively small VDW volume, 58 we then assumed that a novel hinge region binder with more favorable H-bond and VDW interacting capability may improve both the inhibitory potency and oncogenic B-Raf selectivity. Therefore, a substructure-based analogue searching with 2-phenyl-5-vinylfuran (highlighted by red in Figure 2) as a query template was performed to hop the potential hinge region binders, and a focused library comprising of all of the hit compounds was extracted from the SPECS database.…”

Section: Resultsmentioning

confidence: 99%

Development of a novel class of B-RafV600E-selective inhibitors through virtual screening and hierarchical hit optimization

et al. 2012

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Oncogenic mutations in critical nodes of cellular signaling pathways have been associated with tumorigenesis and progression. The B-Raf protein kinase, a key hub in the canonical MAPK signaling cascade, is mutated in a broad range of human cancers and especially in malignant melanoma. The most prevalent B-RafV600E mutant exhibits elevated kinase activity and results in constitutive activation of the MAPK pathway, thus making it a promising drug target for cancer therapy. Herein, we described the development of novel B-RafV600E selective inhibitors via multi-step virtual screening and hierarchical hit optimization. Nine hit compounds with low micromolar IC50 values were identified as B-RafV600E inhibitors through virtual screening. Subsequent scaffold-based analogue searching and medicinal chemistry efforts significantly improved both the inhibitor potency and oncogene selectivity. In particular, compounds 22f and 22q possess nanomolar IC50 values with selectivity for B-RafV600E in vitro and exclusive cytotoxicity against B-RafV600E harboring cancer cells.

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Hydrogen Bonding in Nitro Compounds¹

Cited by 23 publications

References 0 publications

Optical Activity of Symmetric Compounds in Chiral Media. I. Induced Circular Dichroism of Unbound Substrates

Optical Activity of Symmetric Compounds in Chiral Media. I. Induced Circular Dichroism of Unbound Substrates

Ultrafast Excited-State Dynamics of Eosin B: A Potential Probe of the Hydrogen-Bonding Properties of the Environment

Development of a novel class of B-RafV600E-selective inhibitors through virtual screening and hierarchical hit optimization

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Hydrogen Bonding in Nitro Compounds1

Cited by 23 publications

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Optical Activity of Symmetric Compounds in Chiral Media. I. Induced Circular Dichroism of Unbound Substrates

Optical Activity of Symmetric Compounds in Chiral Media. I. Induced Circular Dichroism of Unbound Substrates

Ultrafast Excited-State Dynamics of Eosin B: A Potential Probe of the Hydrogen-Bonding Properties of the Environment

Development of a novel class of B-RafV600E-selective inhibitors through virtual screening and hierarchical hit optimization

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Hydrogen Bonding in Nitro Compounds¹