10.1021/jo200954c.s003
Brendan Kelly
Brendan
Kelly
Daniel H. O'Donovan
Daniel H.
O'Donovan
John O'Brien
John
O'Brien
Thomas McCabe
Thomas
McCabe
Fernando Blanco
Fernando
Blanco
Isabel Rozas
Isabel
Rozas
Pyridin-2-yl Guanidine
Derivatives: Conformational
Control Induced by Intramolecular Hydrogen-Bonding Interactions
American Chemical Society
2016
series
dihedral angle
intramolecular interactions
1 H NMR spectra
NMR analysis
guanidinium salts
pyridine N 1 atom
derivative
guanidinium protons
B 3LYP
guanidine
data
Conformational Control Induced
pyridine ring
2016-02-22 14:27:25
Dataset
https://acs.figshare.com/articles/dataset/Pyridin_2_yl_Guanidine_Derivatives_Conformational_Control_Induced_by_Intramolecular_Hydrogen_Bonding_Interactions/2581933
The synthesis and conformational analysis of a series
of pyridin-2-yl
guanidine derivatives using NMR, X-ray crystallography, and B3LYP/6-31+G**
theoretical studies are reported. A remarkable difference was observed
in the <sup>1</sup>H NMR spectra of the guanidinium salts as compared
with their <i>N</i>,<i>N</i>′-di-Boc protected
and neutral analogues. This difference corresponds to a 180°
change in the dihedral angle between the guanidine/ium moiety and
the pyridine ring in the salts as compared to the Boc-protected derivatives,
a conclusion that was supported by theoretical studies, X-ray data,
and NMR analysis. Moreover, our data sustain the existence of two
intramolecular hydrogen-bonding systems: (i) between the pyridine
N1 atom and the guanidinium protons in the salts and (ii) within the <i>tert</i>-butyl carbamate groups of the Boc-protected derivatives.
To verify that the observed conformational control arises from these
intramolecular interactions, a new series of <i>N</i>-Boc-<i>N</i>′-propyl-substituted pyridin-2-yl guanidines were
also prepared and studied.