Long-Range Bonding/Nonbonding Interactions: A Donor Acceptor Resonance Studied by Dynamic NMR

Long-range bonding interactions were evaluated using variable-temperature NMR spectroscopy and suitable 2'-CH2X-substituted phenylpyridines (X = Me, NMe2, OMe, F). It was found that the arylpyridyl rotational barriers were lower when electronegative atoms were bound to the alpha carbon of the 2' moiety. This effect was ascribed to a stabilizing interaction in the transition state due to the lone pair of the heterocyclic nitrogen with the alpha carbon. Computational support for this hypothesis came from CCSD(T)/6-31+G(d) calculations. Steric effects of the X moiety were ruled out by comparison of the rotational barriers of analogous biphenyls.


Published in:
Organic Letters, 17, 11, 2740-2743
Year:
2015
Publisher:
Washington, Amer Chemical Soc
ISSN:
1523-7060
Laboratories:




 Record created 2015-09-28, last modified 2018-01-28


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