Nucleophilic replacement of halogen atom by amino group in 1-halomethyl-o-carboranes

1973 ◽  
Vol 22 (5) ◽  
pp. 1153-1153 ◽  
Author(s):  
L. I. Zakharkin ◽  
V. S. Kozlova
Keyword(s):  
Halogen Atom ◽  
Amino Group ◽  
Nucleophilic Replacement

Synthesis and properties of some gelatin derivatives with substituents at the amino group

1965 ◽  
Vol 15 (10) ◽  
pp. 479-488
Author(s):  
R. C. Clark ◽  
W. G. Cobbett ◽  
J. A. Gibbs ◽  
R. T. Jones ◽  
A. A. Leach ◽  
...  
Keyword(s):  
Amino Group

Reductive Dehalogenation of Environmental Contaminants: A Critical Review

1989 ◽  
Vol 24 (2) ◽  
pp. 299-322 ◽  
Author(s):  
R. M. Baxter
Keyword(s):  
Hydrogen Atom ◽  
Aromatic Compounds ◽  
Reductive Dechlorination ◽  
Halogen Atom ◽  
Environmental Contaminants ◽  
Methanogenic Bacteria ◽  
Photochemical Reactions ◽  
Reductive Dehalogenation ◽  
Iron Porphyrins ◽  
Aliphatic Compounds

Abstract It is generally recognized that reductive processes are more important than oxidative ones in transforming, degrading and mineralizing many environmental contaminants. One process of particular importance is reductive dehalogenation, i.e., the replacement of a halogen atom (most commonly a chlorine atom) by a hydrogen atom. A number of different mechanisms are involved in these reactions. Photochemical reactions probably play a role in some instances. Aliphatic compounds such as chloroethanes, partly aliphatic compounds such as DDT, and alicyclic compounds such as hexachlorocyclohexane are readily dechlorinated in the laboratory by reaction with reduced iron porphyrins such as hematin. Many of these are also dechlorinated by cultures of certain microorganisms, probably by the same mechanism. Such compounds, with a few exceptions, have been found to undergo reductive dechlorination in the environment. Aromatic compounds such as halobenzenes, halophenols and halobenzoic acids appear not to react with reduced iron porphyrins. Some of these however undergo reductive dechlorination both in the environment and in the laboratory. The reaction is generally associated with methanogenic bacteria. There is evidence for the existence of a number of different dechlorinating enzymes specific for different isomers. Recently it has been found that many components of polychlorinated biphenyls (PCBs), long considered to be virtually totally resistant to environmental degradation, may be reductively dechlorinated both in the laboratory and in nature. These findings suggest that many environmental contaminants may prove to be less persistent than was previously feared.

Aminocoumarins: A Privileged Precursor for the Synthesis of Fused Heterocycles

2019 ◽  
Vol 23 (9) ◽  
pp. 1045-1075 ◽  
Author(s):  
Saigal ◽  
Sumbulunnisan Shareef ◽  
Habibur Rahman ◽  
Md. Musawwer Khan
Keyword(s):  
Chemical Reactivity ◽  
Structural Systems ◽  
Natural Occurrence ◽  
Amino Group ◽  
Active Compounds ◽  
The Past ◽  
Fused Heterocycles

Aminocoumarins are one of the important core structural systems, present in several biologically and medicinally active compounds. Owing to its natural occurrence, potential pharmacological applications and remarkable versatility as a privileged precursor, several proficient synthetic protocols have been reported in the literature over the past years. The presence of an amino group and enamine carbon enhances its chemical reactivity and thus such functionality is repeatedly used for the construction of various fused and simple heterocycles. This review highlights the preparation of different aminocoumarins and their applications for the construction of a variety of five, six and eight membered fused heterocycles.

Substituent Effects on the Basicity of ortho-, meta- and para-substituted N1,N1-Dimethyl-N2-phenylformamidines in Ethanol and in Water

1992 ◽  
Vol 57 (1) ◽  
pp. 113-118
Author(s):  
Ewa Daniela Raczyńska
Keyword(s):  
Quantitative Analysis ◽  
Aqueous Ethanol ◽  
Substituent Effects ◽  
Amino Group

The relative δpKa values of ortho-, meta-, and para-substituted N1,N1-dimethyl-N2-phenylformamidines obtained in 95.6% aqueous ethanol have been compared with those in water. The comparison shows only some differences in the ortho substituent effects. The meta and para substituent effects in ethanol are not very different from those in water. Quantitative analysis of the experimental δpKa values based on the Taft equation has led to separation of the total electromeric effects into the inductive and mesomeric effects. As compared to the amino group in anilines, the formamidine group is more sensitive to the transmission of the inductive than the mesomeric effects.

Induced Smectic Phases II. Influence of the Amino Substituent on the Induction of Smectic Phases

1981 ◽  
Vol 36 (10) ◽  
pp. 1086-1091 ◽  
Author(s):  
F. Schneider ◽  
N. K. Sharma
Keyword(s):  
Liquid Crystal ◽  
Electron Donor ◽  
Amino Group ◽  
Donor Property ◽  
Smectic Phases ◽  
Ct Complexes ◽  
Induced Smectic Phases

The diagrams of state have been studied for some liquid crystal mixtures which show the induction of smectic phases. Each of the systems studied contains one component with an amino group which influences the polarity and the electron donor property of the molecules. The discussion of the diagrams of state, of the thickness of the smectic layers and of the colours of the mixtures, which indicate the formation of CT complexes, shows that existing models can not explain the induction of smectic phases.

scholarly journals The site of attachment of retinal in bacteriorhodopsin. The epsilon-amino group in Lys-41 is not required for proton translocation.

1982 ◽  
Vol 257 (15) ◽  
pp. 8596-8599 ◽  
Author(s):  
K S Huang ◽  
M J Liao ◽  
C M Gupta ◽  
N Royal ◽  
K Biemann ◽  
...  
Keyword(s):  
Proton Translocation ◽  
Amino Group

scholarly journals Catalytic Antioxidant Activity of Bis-Aniline-Derived Diselenides as GPx Mimics

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4446
Author(s):  
Giancarlo V. Botteselle ◽  
Welman C. Elias ◽  
Luana Bettanin ◽  
Rômulo F. S. Canto ◽  
Drielly N. O. Salin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Hydrogen Bond ◽  
Electronic Properties ◽  
Partial Charge ◽  
Amino Group ◽  
Diphenyl Diselenide ◽  
Charge Delocalization ◽  
Ipso Substitution ◽  
Efficient Route ◽  
Catalytic Performances

Herein, we describe a simple and efficient route to access aniline-derived diselenides and evaluate their antioxidant/GPx-mimetic properties. The diselenides were obtained in good yields via ipso-substitution/reduction from the readily available 2-nitroaromatic halides (Cl, Br, I). These diselenides present GPx-mimetic properties, showing better antioxidant activity than the standard GPx-mimetic compounds, ebselen and diphenyl diselenide. DFT analysis demonstrated that the electronic properties of the substituents determine the charge delocalization and the partial charge on selenium, which correlate with the catalytic performances. The amino group concurs in the stabilization of the selenolate intermediate through a hydrogen bond with the selenium.

Engineering Functional Nanomaterials Through the Amino Group

2021 ◽  
pp. 285-340
Author(s):  
Giacomo Filippini ◽  
Paolo Pengo ◽  
Susanna Bosi ◽  
Giulio Ragazzon ◽  
Lucia Pasquato ◽  
...  
Keyword(s):  
Amino Group ◽  
Functional Nanomaterials
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