Table 1. Optimization Reactions.
entry | base | solvent | concn (M) | temp (°C) | time (h) | yielda (%) |
---|---|---|---|---|---|---|
1 | Na2CO3 | TFE | 0.25 | rt | 4 | 94 |
2 | Na2CO3 | TFE | 0.25 | 0 | 6 | 61 |
3b | Na2CO3 | TFE | 0.25 | rt | 6 | 91 |
4 | Na2CO3 | THF | 0.25 | rt | 18 | no rxn |
5 | NEt3 | HFIP | 0.25 | rt | 16 | 42 |
6 | K2CO3 | HFIP | 0.25 | rt | 8 | 40 |
7 | Cs2CO3 | HFIP | 0.25 | rt | 12 | 46 |
8 | Na2CO3 | HFIP | 0.25 | rt | 4 | 89 |
9b | Na2CO3 | HFIP | 0.25 | rt | 18 | 66 |
10 | Na2CO3 | HFIP | 0.50 | rt | 6 | 39 |
Isolated yield.
2 equiv of indole, 1 equiv of haloamide.