Table 1. Screening of Temperature in [4 + 2] and [4 + 1] Cycloadditions.
| entry | reactant | product | temp. (°C) | time (h) | yield (%)a |
|---|---|---|---|---|---|
| 1 | 6 | 7 | 100 | 24 | 33 |
| 2 | 2 | 3 | 100 | 24 | trace |
| 3 | 2 | 3 | 120 | 24 | 59 |
| 4 | 2 | 3 | 135 | 24 | 83 |
| 5 | 2 | 3 | 150 | 16 | 78 |
Isolated yield.
| entry | reactant | product | temp. (°C) | time (h) | yield (%)a |
|---|---|---|---|---|---|
| 1 | 6 | 7 | 100 | 24 | 33 |
| 2 | 2 | 3 | 100 | 24 | trace |
| 3 | 2 | 3 | 120 | 24 | 59 |
| 4 | 2 | 3 | 135 | 24 | 83 |
| 5 | 2 | 3 | 150 | 16 | 78 |
Isolated yield.