Table 1. Screening Reaction Conditionsa.
| entry | X | atm. | base | solvent | yieldd |
|---|---|---|---|---|---|
| 1 | 3 | air | K2CO3 | 1,4-dioxane | 41% |
| 2 | 10 | air | K2CO3 | 1,4-dioxane | 62% |
| 3 | 100 | air | K2CO3 | 1,4-dioxane | 87% |
| 4 | 10 | air | K2CO3 | tert-butanol | 4% |
| 5 | 10 | air | K2CO3 | MeOH | 59% |
| 6 | 10 | air | K2CO3 | THF | 51% |
| 7 | 10 | air | K2CO3 | EtOAc | 65% |
| 8 | 10 | air | K2CO3 | DCM | 14% |
| 9 | 10 | air | TMEDA | 1,4-dioxane | 67% |
| 10 | 10 | air | DBU | 1,4-dioxane | 19% |
| 11 | 10 | air | KOH | 1,4-dioxane | 14% |
| 12 | 10 | air | DIPEA | 1,4-dioxane | 12% |
| 13 | 10 | N2 | K2CO3 | 1,4-dioxane | NR |
| 14 | 10b | air | K2CO3 | 1,4-dioxane | 82% |
| 15 | 10c | air | K2CO3 | 1,4-dioxane | 80% |
Unless otherwise noted, all of the reactions were run with 1a (2.1 mmol), 2a (2.5 equiv), and base (2.0 equiv) under air in 10.0 mL of solvent. Equivalents (equiv) refer to the mole ratio to aniline.
Content value of Cu(BF4)2/AC was 7.7 mass %.
Content value of Cu(BF4)2/AC was 15.4 mass %.
Isolated yields.
