Table 1.
Reaction conditions surveyed for conversion of the vinyl bisphosphonate 10 to the reduced product 11.
| |||||
|---|---|---|---|---|---|
| Entrya | Ligand | Mol % CuOAc2·H2O | T (°C) | Time (h) | Conv (%)b |
| 1 | None | 10 | 70 | 48 | 90 |
| 2 | DPPBZ | 10 | 70 | 1 | >99 |
| 3 | DPPBZ | 10 | 25 | 1 | >99 |
| 4 | DPPM | 10 | 25 | 12 | 95 |
| 5 | DPPF | 10 | 25 | 1 | >99 |
| 6 | DPPE | 10 | 25 | 1 | >99 |
| 7 | BINAP | 10 | 25 | 1 | >99 |
| 8 | DPPV | 10 | 25 | 1 | >99 |
| 9 | DPPBZ | 5 | 25 | 1 | >99 |
| 10 | DPPBZ | 2.5 | 25 | 1 | 50 |
| 11 | DPPBZ | 1 | 25 | 1 | 0 |
a
Reactions were conducted in toluene, on a 1 mmol scale, with a 1:1 ratio of Cu(OAc)2 to ligand (except for entry #1).
b
Conversions were determined by 31P NMR analysis.