15N NMR spectra, tautomerism and diastereomerism of 4,5-dihydro-1H-1,2,3-triazoles

Despite the great number of 4,5-dihydro-1H-1,2,3-triazoles synthesized, N-15 NMR data of these heterocycles are extremely rare. The aim of this paper is to present such data and examples of their application. The Compounds investigated have been synthesized according to the given references or procedures. Their N-15 NMR spectra were measured at natural abundance. For some compounds, the chemical shift assignments were confirmed with the help of N-15 labelled material. The influences on N-15 chemical shifts of substitution pattern, solvent and concentration were investigated. Additionally, some lanthanide induced shift (LIS) investigations were performed. C-13 labelled compounds were employed as tools to provide the assignment of tautomeric structures.