Table 1. Computed Activation and Reaction Energies (in kcal/mol), Synchronicity (Sy), and NICS(3,+1) Values in the Corresponding TSs (in ppm) of the Considered Carbonyl-Ene Reactions.
| catalyst | ΔG≠a | ΔE≠a | ΔGRb | ΔERb | Sy | NICS(3,+1) |
|---|---|---|---|---|---|---|
| none | 44.1 | 31.3 | –2.6 | –14.7 | 0.87 | –19.9 |
| Cl2 | 43.8 | 28.7 | –1.9 | –16.1 | 0.72 | –16.9 |
| Br2 | 41.7 | 26.8 | –2.9 | –16.6 | 0.68 | –15.9 |
| BMe3 | 34.8 | 19.8 | –4.1 | –18.5 | 0.62 | –13.5 |
| BPh3 | 28.0 | 14.1 | –6.0 | –19.6 | 0.58 | –11.2 |
| SnCl4 | 27.4 | 13.8 | –3.4 | –17.8 | 0.61 | –9.9 |
| AlMe2Cl | 25.8 | 11.6 | –6.1 | –19.8 | 0.59 | –10.3 |
| FeF3 | 26.4 | 11.6 | –3.2 | –18.3 | 0.60 | –9.6 |
| FeCl3 | 24.0 | 9.5 | –3.8 | –18.4 | 0.58 | –8.2 |
| FeBr3 | 21.8 | 7.6 | –5.7 | –20.0 | 0.58 | –8.0 |
| InCl3 | 24.7 | 10.4 | –6.7 | –20.2 | 0.61 | –10.5 |
| TiCl4 | 24.0 | 10.2 | –3.8 | –17.9 | 0.55 | –6.5 |
| BF3 | 22.4 | 9.2 | –5.9 | –18.8 | 0.58 | –8.8 |
| AlCl3 | 19.3 | 6.1 | –5.7 | –19.0 | 0.56 | –7.8 |
a
Activation barriers computed as ΔE≠ = E(TS) – E(1-butene) – E(aldehyde).
b
Reaction energies computed as ΔER = E((E)-hex-4-en-2-ol) – E(1-butene) – E(aldehyde). All data have been computed at the PCM(dichloromethane)-ωB97xD/def2-TZVPP//PCM(dichloromethane)-ωB97xD/def2-SVP level.