Stanovnik, B
1987
Correlation of Ring Nitrogen Substituents with Carbon-13 Nuclear Magnetic Resonance Data in Azoloazines
Pugmire, R.J.; Smith, J.C.; Grant, D.M.; Stanovnik, B.; Tisler, M. and Vercek, B.
J. Heterocyclic Chem, 24, 805-809, 1987. 5 pgs. Funded by Institute of General Medical Sciences of the National Institutes of Health and by the Council of Yugoslav Academies, the Slovene Academy of Science and Arts, and the US National Academy of Sciences.
Carbon-13 nuclear magnetic resonance data have been acquired on 22 azoloazines. Chemical shifts have been correlated by a step-wise linear multiple regression with nitrogen substituents in both the 5- and 6- membered rings using pyrrolo [1,2-a] pyridine as the reference for chemical shift correlation. The data demonstrate that a highly correlated set of chemical shift parameters exist. Nitrogen substitution in the five-membered ring produces larger cross-ring effects than is observed in the five-membered ring when substitution occurs in the six-membered ring. Within the six-membered ring a constant para-substituent parameter is noted. The meta- and para- parameters are more complex and fall into two groups for each parameter. Within the five-membered ring, a highly regular chemical shift pattern is observed which reflects an attenuated perturbation from nitrogen substitution in the six-membered ring.
Stanovnik, B
1987
Correlation of Ring Nitrogen Substituents with Carbon-13 Nuclear Magnetic Resonance Data in Azoloazines
Pugmire, R.J.; Smith, J.C.; Grant, D.M.; Stanovnik, B.; Tisler, M. and Vercek, B.
J. Heterocyclic Chem, 24, 805-809, 1987. 5 pgs. Funded by Institute of General Medical Sciences of the National Institutes of Health and by the Council of Yugoslav Academies, the Slovene Academy of Science and Arts, and the US National Academy of Sciences.
Carbon-13 nuclear magnetic resonance data have been acquired on 22 azoloazines. Chemical shifts have been correlated by a step-wise linear multiple regression with nitrogen substituents in both the 5- and 6- membered rings using pyrrolo [1,2-a] pyridine as the reference for chemical shift correlation. The data demonstrate that a highly correlated set of chemical shift parameters exist. Nitrogen substitution in the five-membered ring produces larger cross-ring effects than is observed in the five-membered ring when substitution occurs in the six-membered ring. Within the six-membered ring a constant para-substituent parameter is noted. The meta- and para- parameters are more complex and fall into two groups for each parameter. Within the five-membered ring, a highly regular chemical shift pattern is observed which reflects an attenuated perturbation from nitrogen substitution in the six-membered ring.