Diarylamines with the neighboring pyridyl group: synthesis and modulation of the amine functionality via intramolecular H-bonding

Synthesis ◽  
2021 ◽  
Author(s):  
Tatiana V. Magdesieva ◽  
Oleg A. Levitskiy ◽  
Ivan A. Klimchuk ◽  
Yuri K. Grishin ◽  
Vitaly A. Roznyatovsky ◽  
...  
Keyword(s):  
Activation Energy ◽  
Reductive Amination ◽  
Boronic Acids ◽  
Oxidation Potential ◽  
Amino Group ◽  
Dynamic Nature ◽  
Polar Solvents ◽  
Pyridyl Group ◽  
Phenyl Rings ◽  
Chelating Effect

New pyridyl-containing diarylamines were obtained via Cu-assisted reductive amination of the ortho-2-pyridylaryl boronic acids. Comparative analysis of the spectral and electrochemical data obtained for new diarylamines and their pyridyl-free counterparts revealed the intramolecular H-bond (IMHB) formation which significantly influences the properties of the amino group. The electron density at the N atom of the amino group is increased due to partial weakening of the N-H bond, although the BDE and activation energy for the H-atom abstraction is increased due to the chelating effect of two N atoms. The ortho-pyridyl-containing diarylamines are more prone to be oxidized as compared to their pyridyl-free counterparts; the shift in the oxidation potential values correlates with the strength of the intramolecular H-bonding which can be tuned by inserting substituents in the pyridyl or phenyl rings. The IMHB is reserved even in polar solvents having a significant H-acceptor ability (such as DMSO) but can be destroyed in methanol, testifying in favor of the dynamic nature of the H-bonding.

Cu(I)-Mediated Reductive Amination of Boronic Acids with Nitroso Aromatics

2004 ◽  
Vol 6 (15) ◽  
pp. 2631-2634 ◽  
Author(s):  
Ying Yu ◽  
Jiri Srogl ◽  
Lanny S. Liebeskind
Keyword(s):  
Reductive Amination ◽  
Boronic Acids

scholarly journals Crystal structure of 2-(2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ylidene)acetonitrile

2015 ◽  
Vol 71 (10) ◽  
pp. o792-o793
Author(s):  
K. Priya ◽  
K. Saravanan ◽  
S. Kabilan ◽  
S. Selvanayagam
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Chair Conformation ◽  
Equatorial Orientation ◽  
Amino Group ◽  
Phenyl Rings

In the title 3-azabicyclononane derivative, C22H22N2, both the fused piperidine and cyclohexane rings adopt a chair conformation. The phenyl rings attached to the central azabicylononane fragment in an equatorial orientation are inclined to each other at 23.7 (1)°. The amino group is not involved in any hydrogen bonding, so the crystal packing is stabilized only by van der Waals forces.

scholarly journals The origin of the solvent dependence of fluorescence quantum yields in dipolar merocyanine dyes

2019 ◽  
Vol 10 (48) ◽  
pp. 11013-11022 ◽  
Author(s):  
Joscha Hoche ◽  
Alexander Schulz ◽  
Lysanne Monika Dietrich ◽  
Alexander Humeniuk ◽  
Matthias Stolte ◽  
...  
Keyword(s):  
Activation Energy ◽  
Energy Barrier ◽  
Conical Intersection ◽  
Quantum Yields ◽  
Fluorescence Lifetimes ◽  
Activation Energy Barrier ◽  
Polar Solvents ◽  
Fluorescence Quantum Yields ◽  
Solvent Dependence ◽  
Merocyanine Dyes

An increasing activation energy barrier to a conical intersection was identified as the reason for higher fluorescence lifetimes and quantum yields for merocyanines in polar solvents.

REACTION OF TRICHLOROACETONITRILE WITH PRIMARY AND SECONDARY AMINES: PART II. INFRARED SPECTRA OF N-SUBSTITUTED TRICHLOROACETAMIDINES

1959 ◽  
Vol 37 (4) ◽  
pp. 795-802 ◽  
Author(s):  
John C. Grivas ◽  
Alfred Taurins
Keyword(s):  
Infrared Spectra ◽  
Secondary Amines ◽  
Amino Group ◽  
Polar Solvents ◽  
Primary And Secondary Amines ◽  
Secondary Amino ◽  
Solid Phases ◽  
Infrared Absorption Spectra ◽  
Degree Of Association ◽  
Liquid And Solid Phases

A correlation between the infrared absorption spectra and the structure of 13 N-mono- and N-di-substituted trichloroacetamidines is presented. N-Alkyl- and N-aryl-trichloroacetami-dines associate strongly in the liquid and solid phases, and exist only in the imino form in non-polar solvents. They can be characterized by a strong band (amidine II band) at 1510–1525 cm−1 and 1570–1580 cm−1 respectively which is attributed to the deformation vibration [Formula: see text] of the secondary amino group. The degree of association of N-substituted trichloroacetamidines changes in the following order of substitution:[Formula: see text]

Isotopic Exchange of Free Sulfur with Thiurams, Isothiocyanates and Dithiocarbamates

1961 ◽  
Vol 34 (2) ◽  
pp. 600-605
Author(s):  
L. S. Kuzina ◽  
E. N. Guryanova
Keyword(s):  
Activation Energy ◽  
Exchange Rate ◽  
Isotopic Exchange ◽  
Elementary Sulfur ◽  
Amino Group ◽  
Optimal Conditions ◽  
Phenyl Radicals ◽  
The Exchange Rate ◽  
Free Sulfur

Abstract 1. Studies were made concerning the exchangeability, with elementary radioactive sulfur, of sulfur atoms in 15 compounds including thiurams, dithiocarbamate and isothiocyanates. The number of exchangeable sulfur atoms in each material was established, as well as the optimal conditions for exchange, and for seven of the compounds the activation energy for the process was determined. The exchange rate of thiurams, with elementary sulfur, increases with the number of sulfur atoms in the polysulfide chain. In tetramethyl-thiuram tetrasulfide the two middle sulfur atoms are more readily exchanged, while the outer four sulfurs, bonded to carbon, are exchanged less rapidly but not sufficiently so to allow carrying out a separate exchange. 2. The velocity of exchange is significantly reduced in the thiuram disulfides when aliphatic radicals are replaced by phenyl radicals. A difference in the influence of amino-group radical variations was noted between the thiurams and the dithiocarbamates. The results of the isotopic exchange of sulfur in these materials have been considered from the viewpoint of their effectiveness as accelerators in the vulcanization of rubber.

Cu-catalyzed arylation of the amino group in the indazole ring: regioselective synthesis of pyrazolo-carbazoles

2015 ◽  
Vol 13 (5) ◽  
pp. 1481-1491 ◽  
Author(s):  
K. Anil Kumar ◽  
Prakash Kannaboina ◽  
Devendra K. Dhaked ◽  
Ram A. Vishwakarma ◽  
Prasad V. Bharatam ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Boronic Acids ◽  
Regioselective Synthesis ◽  
Amino Group ◽  
Dehydrogenative Coupling

Arylated aminoindazoles were synthesized by copper-catalyzed C–N bond cross-coupling with boronic acids. These were then transformed to pyrazolo-carbazoles by Pd-catalyzed regioselective cross-dehydrogenative coupling.

THE CIS-TRANS ISOMERIZATION OF AZOBENZENE IN SOLUTION

1950 ◽  
Vol 28b (4) ◽  
pp. 140-155 ◽  
Author(s):  
C. A. Winkler ◽  
J. Halpern ◽  
G. W. Brady
Keyword(s):  
Activation Energy ◽  
Internal Pressure ◽  
Solvent Effect ◽  
Chemical Kinetics ◽  
Linear Relation ◽  
Mixed Solvents ◽  
Square Root ◽  
Polar Solvents ◽  
Trans Isomerization ◽  
Kinetics Of

Relations for the solvent effect on the rate of a unimolecular, nonionic reaction are derived, using existing theories of solutions and of chemical kinetics. The kinetics of the cis-trans isomerization of azobenzene were investigated in 16 pure solvents. A linear relation between the activation energy, E, and the square root of the internal pressure of the solvent, (P′S)1/2 was found, in agreement with the theory. Linear relations between log A and E, and between log k and (P′S)1/2 were also found, but the results for the reaction in highly polar solvents deviated significantly from these relations. The kinetics of the reaction in mixed solvents indicate that the azobenzene is preferentially surrounded by the component in which it is more readily soluble.

scholarly journals (4Z)-4-[(2-Chloroanilino)(phenyl)methylidene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

2012 ◽  
Vol 68 (6) ◽  
pp. o1843-o1843
Author(s):  
Li-Ying Xu ◽  
Ning Li ◽  
Jia-Min Li ◽  
Heng-Qiang Zhang ◽  
Zhen-Hai Sun
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Membered Ring ◽  
Dihedral Angles ◽  
Amino Group ◽  
Keto Form ◽  
Compound C ◽  
Phenyl Rings ◽  
Supramolecular Chains

The title compound, C23H18ClN3O, exists in an enamine–keto form with the amino group involved in an intramolecular N—H...O hydrogen bond. The five-membered ring is nearly planar, the largest deviation being 0.0004 (7) Å, and makes dihedral angles of 16.62 (6), 41.89 (5) and 71.27 (4)° with the phenyl rings. In the crystal, weak C—H...O hydrogen bonds link the molecules into supramolecular chains along the b axis.

scholarly journals The FA Polymerization Disruption by Protic Polar Solvent

2018 ◽  
Author(s):  
Guillaume Falco ◽  
Nathanael Guigo ◽  
Luc Vincent ◽  
Nicolas Sbirrazzuoli
Keyword(s):  
Activation Energy ◽  
Isopropyl Alcohol ◽  
Polar Solvent ◽  
Water System ◽  
Polar Solvents ◽  
Continuous Increase ◽  
Exponential Factor ◽  
Rubbery State ◽  
Higher Temperature ◽  
Lower Temperature

Furfuryl alcohol (FA) is a biobased monomer derived from lignocellulosic biomass. The present work describes its polymerization in presence of protic polar solvents, i.e. water or isopropyl alcohol (IPA), using maleic anhydride (MA) as acidic initiator. The polymerization was followed from the liquid to the rubbery state by combining DSC and DMA data. In the liquid state, IPA disrupts the expected reactions during all the FA polymerization due to a stabilization of the furfuryl carbenium center. This causes the initiation of the polymerization at higher temperature, which is also reflected by higher activation energy. In water system, the MA opening allows to start the reaction at lower temperature. A higher pre-exponential factor value is obtained in that case. The DMA study of final branching reaction occurring in the rubbery state has highlighted continuous increase of elastic modulus until 290 °C. This increasing tendency of modulus was exploited to obtain activation energy dependences (Eα) of FA polymerization in the rubbery state.

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