Overall, the invention provides the chemistry for the compounds and for the processes to prepare compounds derived from 1,5-diazacyclooctanes. This makes available high density, high melting point, thermally stable small and medium ring nitrogen heterocycles that may also contain N-nitro, C-nitro or other functional groups. The compounds include cyclooctanes, bicyclo octanes, propellanes and functionalized derivatives of the above compounds. The preparations can include transannular cyclizations. The materials have several applications; e.g., the polynitro compounds are energetic materials.