Table 2 The Henry reaction of 5b with ligand 1e and a range of copper sources, to furnish 6b.
From: Rigid and concave, 2,4-cis-substituted azetidine derivatives: A platform for asymmetric catalysis
| |||||||
|---|---|---|---|---|---|---|---|
Entry | Copper Source | Loading/X mol% | Solvent | Temp./°C | Time/h | Conv./% | E.E./% |
1 | None | 0 | EtOH | 18 | 16 | 0 | — |
2 | None | 5 1e only | EtOH | 18 | 16 | 0 | — |
3 | Cu(OAc)2·H2O | 5 no ligand | EtOH | 18 | 16 | 0 | — |
4 | Cu(OAc)2·H2O | 1 | EtOH | 18 | 48 | 21 | — |
5 | Cu(OAc)2·H2O | 5 | EtOH | 18 | 16 | 88 | 71 |
6 | Cu(OAc)2·H2O | 10 | EtOH | 18 | 16 | 83 | 62 |
7 | Cu(OAc) | 5 | EtOH | 18 | 16 | 82 | 55 |
8 | CuSO4·5H2O | 5 | EtOH | 18 | 16 | 0 | — |
9 | CuCl2·2H2O | 5 | EtOH | 18 | 16 | 0 | — |
10 | Cu(OTf)2 | 5 | EtOH | 18 | 16 | 0 | — |
11 | Cu(OAc)2·H2O | 5 | MeOH | 18 | 16 | 96 | 32 |
12 | Cu(OAc)2·H2O | 5 | i-PrOH | 18 | 16 | 78 | 32 |
13 | Cu(OAc)2·H2O | 5 | THF | 18 | 16 | 43 | 6 |
14 | Cu(OAc)2·H2O | 5 | Et2O | 18 | 16 | 73 | 5 |
15 | Cu(OAc)2·H2O | 5 | Toluene | 18 | 16 | 46 | 39 |
16 | Cu(OAc)2·H2O | 5 | CH2Cl2 | 18 | 16 | 88 | 21 |
17 | Cu(OAc)2·H2O | 5 | CH3CN | 18 | 16 | 86 | 7 |
18 | Cu(OAc)2·H2O | 5 | EtOH | 0 | 48 | 93 | 79 |
19 | Cu(OAc)2·H2O | 5 | EtOH | 40 | 16 | 93 | 64 |
20 | Cu(OAc)2·H2O | 5 | EtOH | 60 | 16 | 98 | 51 |
