This model can be extended to reactions other than the three-membered ring cleavage in which electronic delocalization can operate simultaneously with strain release. We have compiled a dataset encompassing strain release energies and 2-Nocc values for various bonds types across commonly-employed strained molecules, including carbocycles, heterocycles, cycloalkynes and cycloalkenes (Figure and ). For example, the principle that more delocalized bonds are intrinsically more reactive is found to apply to reactions such as strain-releasing 'click' (3+2) azide-alkyne cycloadditions. Strategies to accelerate such reactions have primarily focused on increasing the strain of the alkyne, for example by incorporating the alkyne into a medium-sized ring. Significant efforts have been undertaken to understand reactivity patterns in these reactions using the distortion/interactionactivation/strain (DI-AS) model, which has identified both enhanced alkyne distortion and greater inter-fragment interactions as factors that reduce TS barriers. A BEP analysis of the cycloaddition between methyl azide and a range of alkynes (Figure ) reveals a loose correlation (R 2 = 0.67) between the reaction driving force (∆Hr) and the activation barrier (∆H ‡ ) with a reasonably low RMSE (2.3 kcal mol -1 ). This result suggests that, in general, strain release does enhance alkyne reactivity, causing faster cycloadditions as the ring size decreases from 10 (A3) to 7 (A10).