Table 2.
Enantioselective Cu-Catalyzed Multicomponent Borylation/1,2-Addition of Vinyl-B(pin) to Aryl, Alkenyl and Alkyl Aldehydesa
| |||||
|---|---|---|---|---|---|
|
| |||||
| entry | product | isolated yield (%)d | isolated dr (anti syn)b | erc | |
| 1 | 2a | G = Ph | 74 | >20:1 | 96:4 |
| 2 | 2b | G=p-FC6H4 | 70 | >20:1 | 96:4 |
| 3 | 2c | G = p-BrC6H4 | 68 | 5.7:1 | 95:5 |
| 4 | 2d | G = p-OMeC6H4 | 70 | >20:1 | 94:6 |
| 5e | 2e | G =m-MeC6H4 | 75(77) | >20:1 (4:1) | 95:5 |
| 6 | 2f | G = o-MeC6H4 | 81 | >20:1 | 96:4 |
| 7 | 2g | G = o-BrC6H5 | 83 | >20:1 | 96:4 |
| 8 | 2h |
|
63 | 3:1 | 94:6 |
| 9e | 2i |
|
52 (57) | >20:1 (3.5:1) | 97:3 |
| 10 | 2j |
|
71 | >20:1 | 95:5 |
| 11 | 2k |
|
18t | – | – |
| 12 | 2I |
|
78 (36) | >20:1 (>20:1 dr) | 93:7 |
| 13 | 2m |
|
63 | >20:1 | 92:8 |
| 14 | 2n |
|
48 | >20:1 | 75:25 |
| 15e | 2o |
|
70t (52) | 3:1 (3:1) | 90:10 |
a–c
See Table 1.
d
Isolated yield of the anti diastereoisomer unless otherwise stated.
e
Values in parentheses correspond to the TBS protected hydroxydiboronate, resulting from protection of the crude reaction mixture (see Supporting Information for details).
f
NMR yield.