Synthesis 2022; 54(06): 1601-1612
DOI: 10.1055/a-1683-0315
paper

Diarylamines with the Neighboring Pyridyl Group: Synthesis and Modulation of the Amine Functionality via Intramolecular H-Bonding

Oleg A. Levitskiy
a   Lomonosov Moscow State University, Dept. of Chemistry, Leninskie Gory 1/3, Moscow 119991, Russian Federation
,
Ivan A. Klimchuk
a   Lomonosov Moscow State University, Dept. of Chemistry, Leninskie Gory 1/3, Moscow 119991, Russian Federation
,
Yuri K. Grishin
a   Lomonosov Moscow State University, Dept. of Chemistry, Leninskie Gory 1/3, Moscow 119991, Russian Federation
,
Vitaly A. Roznyatovsky
a   Lomonosov Moscow State University, Dept. of Chemistry, Leninskie Gory 1/3, Moscow 119991, Russian Federation
,
Boris N. Tarasevich
a   Lomonosov Moscow State University, Dept. of Chemistry, Leninskie Gory 1/3, Moscow 119991, Russian Federation
,
a   Lomonosov Moscow State University, Dept. of Chemistry, Leninskie Gory 1/3, Moscow 119991, Russian Federation
b   National Research University Higher School of Economics, Miasnitskaya Str. 20, Moscow 101000, Russian Federation
› Author Affiliations
This work was supported by the Russian Science Foundation (Project number 19-13-00094). The NMR part of this work was supported by M.V. Lomonosov Moscow State University Program of Development.


Abstract

New pyridyl-containing diarylamines were obtained via Cu-assisted reductive amination of the ortho-2-pyridylarylboronic 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.

Supporting Information



Publication History

Received: 03 August 2021

Accepted after revision: 29 October 2021

Accepted Manuscript online:
29 October 2021

Article published online:
29 November 2021

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