Table 2.
| ||||
---|---|---|---|---|
entry | additive/equiv | Pd catalyst | 7:8:9a | yield of 9 (%)a |
1 | pyridine/1.0b | Pd-QPhos-G3 | 6:1:1 | 5 |
2 | DMAP/1.0b | Pd-QPhos-G3 | 1:1:4 | 17 |
3 | DMAP/1.0 | Pd-QPhos-G3 | 2:1:3 | 34 |
4 | DMAP/1.0 | Pd-Pt-Bu3-G3 | 4:1:2 | 14 |
5 | DMAP/1.0 | Pd-APhos-G3 | 1:1:5 | 27 |
6 | DMAP/1.0 | Pd-Pt-Bu2CH2t-Bu-G3 | 1:1:11 | 68 |
7 | DMAP/1.0c | Pd-Pt-Bu2CH2t-Bu-G3 | 2:1:13 | 67 |
8 | DMAP/2.0c | Pd-Pt-Bu2CH2t-Bu-G3 | 1:1:>20 | 61 |
9 | DMAP/2.0c | [Pd-G3]2 | n.d. | <2 |
10 | DMAP/2.0c,d | Pd-Pt-Bu2CH2t-Bu-G3 | n.d. | <2 |
Yield and (1,2):(1,4) determined by 1H NMR analysis using 1,3,5-trimethoxybenzene as an internal standard.
Reaction run with 1.5 equiv of (Bpin)2 and 2.0 equiv of KOt-Bu.
Reaction run at 45 °C instead of 22 °C.
Reaction run with 5 mol% CuBr instead of 5 mol% It-BuCuBr. n.d. = not determined