The three energetic minima for each warhead from Figure were reoptimized (without any geometry constraints) to obtain their respective enolate intermediates, and thermal corrections to the electronic energies were calculated in order to determine relative Gibbs free energies. Table summarizes the structural and energetic characteristics of the three enolate rotamers for each warhead and Figure shows the Newman projections for the three minima. The enolates considered herein are also the most energetically stable as compared to their Z-stereoisomers and other conformations based on the pyramidalization at the nitrogen, as can be seen in Table and visualized in Figure . As shown in Table , there is no noticeable change in r min as the terminal group on the warhead size is increased. However, there is a clear correlation between ∆G and Θ min . In particular, synclinal addition of methanethiolate at Θ min ≈ 50 • consistently has negative ∆G values for all warheads and is thus energetically favorable for all warheads. However, antiperiplanar addition of methanethiolate at Θ min ≈ 180 • consistently has positive ∆G values and is thus energetically unfavorable. Finally, synclinal addition at a dihedral angle of Θ min ≈ 310 • results in ∆G values that fluctuate around 0 kcal mol -1 , indicating a finely balanced equilibrium between the isolated reactants and the enolate product. The greater stability of synclinal rotamers over antiperiplanar have been reported for other thio-Michael additions, and our findings are thus broadly in agreement with literature findings. However, these studies did not report a second synclinal energetic minimum, which is most likely because they did not perform Θ-dependent PES scans and only focused on the differences between synclinal versus antiperiplanar addition.