Table 4.
Enantioselective Synthesis of Tetrahydroisoquinolinesa
| ||||
|---|---|---|---|---|
| Entry | R–X | Product | Yield (%)b | er |
| 1 | p-MeO-C6H4–Br | 6a | 51 | 93:7 |
| 2 | p-MeO-C6H4–I | 6a | 52 | 93:7 |
| 3 | o-MeO-C6H4–I | 6b | 42 | 80:20 |
| 4 | p-CF3-C6H4–Br | 6c | 72 | 93:7 |
| 5 |
|
6d | 61 | 93:7 |
| 6 | PhBr | 6e | 69 | 94:6 |
| 7c | PhBr | 6e | 64 | 95:5 |
| 8 |
|
6f | 56 | 93:7 |
| 9c |
|
6f | 55 | 94:6 |
Conditions: 1.0 equiv 5, 1.2 equiv R–X, 1.2 equiv NaOtBu, 2 mol % Pd2(dba)3, 6 mol % (S)-Siphos-PE, toluene (0.125 M), 90 °C, 2 h.
Isolated yield (average of two or more runs).
The reaction was conducted at 70 °C for 12-14 hrs.