Conditions optimizationa.
Entry | Variation from standard conditions | 4Aa b/% |
---|---|---|
1 | None | 88 |
2 | P(p-anisyl)3 instead of L1 | 81 |
3 | PPh3 instead of L1 | 58 |
4 | P(C6F5)3 instead of L1 | 0 |
5 | DPEphos (10 mol%) instead of L1 | 92 |
6 | Without L1 | 0 |
7 | LiOtBu instead of NaH | 2 |
8 | Cs2CO3 instead of NaH | 0 |
9 | Without 3 Å MS | 71 |
10 | 3a′ was used instead of 3ac | 62 |
11 | Cyclohexane instead of toluene | 54 |
Conditions: 1A (0.20 mmol), 2 (0.20 mmol), 3a (0.20 mmol), Pd(OAc)2 (5.0 mol%), L1 (20 mol%), NaH (1.0 equiv.), 3 Å MS (50 mg), toluene (1.0 mL), 60 °C, 12 h.
NMR yield.
Without NaH and 3 Å MS at 70 °C.