Table 1 Optimization of conditions for catalytic asymmetric electrochemical allylic 4-pyridinylationa
From: Palladium-catalyzed asymmetric allylic 4-pyridinylation via electroreductive substitution reaction
| |||||
|---|---|---|---|---|---|
Entry | Deviation from initial conditions | Ligand | Yield | B/L | ee of 3a |
1 | None | L1 | 74 | 8:1 | 70% |
2 | MeCN only | L1 | trace | ||
3 | DMF only | L1 | 54 | 2:1 | 11% |
4 | Et4NBF4 instead of Et4NCl | L1 | 60 | 5:1 | 65% |
5 | None | L2 | 78 (76)b | 13:1 | 93% (R) |
6 | None | L3 | 73 | 6:1 | 50% |
7 | None | L4 | 28 | 6:1 | 22% |
8 | None | L5 | 66 | 10:1 | 90% |
9 | None | L6 | 40 | 4:1 | −77% |
10 | None | L7 | trace | ||
11 | None | L8 | n. d. | ||
12 | Zn or Mg instead of electricity | L1 | n. r. | ||
13 | No Pd catalyst | / | n. r. | ||
