Table 2.
Ni(cod)2/P(SiMe3)3-Catalyzed Diborylative Coupling.
 | ||||
|---|---|---|---|---|
| entry | aldehyde | product | d.r.a | % yieldb |
| 1 |  |
 |
>20:1 | 67 |
| 2 |  |
 |
>20:1 | 73 |
| 3 |  |
 |
>20:1 | 64 |
| 4 |  |
 |
>20:1 | 57 |
| 5 |  |
 |
>20:1 | 57 |
| 6 |  |
 |
>20:1 | 55 |
| 7 |  |
 |
>20:1 | 54 |
| 8 |  |
 |
>20:1 | 58c |
| 9 |  |
 |
>20:1 | 50c |
| 10 |  |
 |
>20:1 | 45c |
| 11 |  |
 |
>20:1 | 37c |
| 12 |  |
 |
6:1d | 49c |
(a)
Determined by 1H NMR analysis of unpurified reaction mixture.
(b)
Isolated yield of purified material. Value is an average of two experiments.
(c)
Run with 1.1 equiv of diene and 1.2 equiv of B2(pin)2.
(d)
Ratio refers to Felkin:anti Felkin selectivity. Reaction for 24 h.