Pyridin-2-yl Guanidine Derivatives: Conformational Control Induced by Intramolecular Hydrogen-Bonding Interactions.
Citation:
Kelly B, O'Donovan DH, O'Brien J, McCabe T, Blanco F, Rozas I, Pyridin-2-yl Guanidine Derivatives: Conformational Control Induced by Intramolecular Hydrogen-Bonding Interactions., The Journal of organic chemistry, 76, 22, 2011, 9216-27Download Item:
PyrGua_rev2_30Sep2011.pdf (Published (author's copy) - Peer Reviewed) 1.036Mb
Abstract:
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 1H NMR spectra of the guanidinium salts
compared with their N,N?-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 compared to the Boc protected derivatives; a conclusion which was
supported by theoretical studies, X-ray data and NMR analysis. Moreover, our data sustains
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 tert-butyl carbamate groups
of the Boc protected derivatives. To verify that the observed conformational control arises
from these intramolecular interactions, a new series of N-Boc-N?-propyl substituted pyridin-2-
yl guanidines was also prepared and studied.
Sponsor
Grant Number
Science Foundation Ireland (SFI)
Higher Education Authority (HEA)
Irish Research Council for Science and Engineering Technology (IRCSET)
Author's Homepage:
http://people.tcd.ie/rozasiDescription:
PUBLISHED
Author: ROZAS, ISABEL
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Journal ArticleCollections:
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The Journal of organic chemistry76
22
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Full text availableDOI:
http://dx.doi.org/10.1021/jo200954cISSN:
0022-3263Licences: