Question #45006

The uncatalyzed nucleophilic acyl substitution of a standard peptide bond at $298\text{ K}$ is extremely slow due to $n \rightarrow \pi^*$ resonance, which provides $\sim 85\text{ kJ mol}^{-1}$ of stabilization. This resonance gives the \ce{C-N} bond a partial double bond character (bond order $\approx 1.4$) and forces the nitrogen into an $sp^2$ hybridization. To accelerate hydrolysis, certain proteases mechanically distort the substrate, twisting the peptide bond dihedral angle ($\omega$) by nearly $90^\circ$. This catalytic strategy is structurally mimicked by the highly reactive synthetic twisted amide, 1-azabicyclo[2.2.2]octan-2-one. In this fully twisted, orthogonal conformation, what are the effective \ce{C-N} bond order and the idealized hybridization state of the nitrogen atom, respectively?