Copper-free click reactions between a dibenzoazocine derivative and azides derived from 5-methyluridine were investigated. The non-catalyzed reaction yielded both regioisomers in an approximately equivalent ratio.
The NMR spectra of each regioisomer revealed conformational isomery. The ratio of isomers was dependent on the type of regioisomer and the type of solvent.
The synthesis of various analogs, a detailed NMR study and computational modeling provided evidence that the isomery was dependent on the interaction of the azocine and pyrimidine parts.