The consideration of propellane-like structures whose bridgehead atoms are boron and nitrogen rather than carbon permits a study of B-N bonding and the effects of inverted tetrahedral configurations at these atoms. We analyze these systems primarily by ab initio structure calculation and the atoms-in-molecules properties method. The borazane molecule and its hexamethyl derivative, whose B-N bonds incontrovertibly exist, serve as the starting point. It is found that boraza[3.3.3]propellane resembles hexamethylborazane in its bond length, dipole moment and BN bond critical point. In contrast boraza[2.2.2]propellane does not exist as such but rather has the open form, 1-aza-4-borabicyclo[2.2.2]octane. Boraza[1.1.1]propellane is found to be kinetically stable in C 3 v symmetry; it has a short B-N bond length but no bond critical point of its electronic charge density on the B-N axis.