Ring-fused hexahydro-1,2,4,5-tetrazines: synthesis, structure, and mechanistic studies on isolable rotational isomers

Abstract

We designed conformationally stable rotational isomers around the C(sp²)–C(sp³) axis at the C₃-position of hexahydro-1,2,4,5-tetrazines. Isolation of each rotamer by silica gel column chromatography was successfully achieved at room temperature. The proposed isomerization mechanism of the rotamers was supported by NMR kinetic studies.