Table 2. Calculated DFT-B3LYP Total Energies for the Two Possible Z- and E-Isomeric Enamine (3)–Imine (4) Tautomers.
| product | Z-enamine form energya | E-enamine form energya | imine form energya | ΔEaE-enamine–imine | ΔEaE-enamine– Z-enamine |
|---|---|---|---|---|---|
| 3a | –955.977 | –955.990 | –955.918 | –0.072 | –0.013 |
| 3b | –996.722 | –996.743 | –996.671 | –0.072 | –0.021 |
| 3c | –1028.131 | –1034.645 | –1034.573 | –0.072 | –6.514 |
| 3d | –1067.169 | –1073.967 | –1073.888 | –0.079 | –6.798 |
| 3e | –1109.516 | –1109.537 | –1109.472 | –0.065 | –0.021 |
| 3f | –1148.821 | –1148.855 | –1149.787 | –0.068 | –0.034 |
| 3g | –1181.408 | –1188.169 | –1188.098 | –0.071 | –6.761 |
| 3h | –1220.637 | –1227.468 | –1227.396 | –0.072 | –6.831 |
| 3i | –1026.964 | –1033.434 | –1033.359 | –0.075 | –6.470 |
| 3j | –1071.834 | –1077.981 | –1070.911 | –0.070 | –6.147 |
| 3k | –1105.055 | –1112.092 | –1112.013 | –0.079 | –7.037 |
| 3l | –1144.092 | –1151.412 | –1151.331 | –0.081 | –7.320 |
a
All of the energy values are expressed in Hartree.