Substituent effects on (15)N and (13)C NMR chemical shifts of 5-phenyl-1,3,4-oxathiazol-2-ones: a theoretical and spectroscopic study.

The synthesis and assignment of (15)N and (13)C NMR signals of the 1,3,4-oxathiazol-2-one ring in a series of para-substituted 5-phenyl derivatives are reported. DFT calculations of (15)N and (13)C chemical shifts correspond closely to observed values. Substituent effects are interpreted in terms of the Hammett correlation and calculated bond orders.

Substituent effects on 15N and 13C NMR chemical shifts of 3-phenylisoxazoles: a theoretical and spectroscopic study.

The synthesis and assignment of 15N and 13C NMR signals of the isoxazole ring in a series of para-substituted 3-phenyl derivatives are reported. DFT calculations of 15N and 13C chemical shifts are presented and compared to observed values. Substituent effects are interpreted in terms of the Hammett correlation and calculated bond orders.