The relative enthalpies of the products of each pathway are presented in Figure . The carbamate relative energies (shown in blue) are always exothermic and somewhat sensitive to substituent substitution. They range from -28.9 (R=F) to -9.7 kcal mol -1 (R=SiH 3 ). Highly electronegative substituents such as R=F, OH, and NH 2 make the carbamate more favorable than the reactants relative to the R=H case. This is likely associated with the aforemen- for scatterplot between substituted M1 and M2 relative enthalpies), but this is partially due to an intramolecular interaction originating from the substituent hydroxyl group. The imidic acid products are much more sensitive to substituent selection, which is unsurprising as NBO analysis of the parent imidic acid predicts significantly more delocalization into the C-N* orbital compared to the carbamate. The imidic acid enthalpies relative to the reactants range from -18.3 (R=F) to 9.2 (R=SiH 3 ) kcal mol -1 and many of the alkyl substituted imidic acid products are predicted to be slightly less thermodynamically favored than the reactants. There is no case where the imidic acid arrangement is lower in energy than the carbamate analogue. The closest the two isomers get in energy is 10.1 kcal mol -1 (R=F), indicating that they are unlikely to be thermodynamically competitive in any case. Assuming no catalyst, our data supports that the H 2 O + RNCO reaction would favor proceeding through the TS1 pathway independent of substituent.