Table 3.
Copper-catalyzed asymmetric [4+1] cycloadditions: Scope
 | |||||
|---|---|---|---|---|---|
| entry | R | R1 | yield (%)a | dr | ee (%) |
| 1 | Ph | Ph | 79 | 13:1 | 85 |
| 2 | 4-(F3C)C6H4 | Ph | 59 | 19:1 | 76 |
| 3 | 4-ClC6H4 | Ph | 77 | 19:1 | 88 |
| 4b | 4-(MeO)C6H4 | Ph | 84 | 19:1 | 92 |
| 5 | Ph | 4-ClC6H4 | 81 | >20:1 | 88 |
| 6 | Ph | 4-(MeO)C6H4 | 84 | 9:1 | 93 |
| 7 | N-Boc-2-pyrrolyl | Ph | 68 | >20:1 | 93 |
| 8 | Ph | 3-furyl | 63 | 6:1 | 87 |
| 9 | Ph | CH=CHPh | 76 | 7:1 | 93 |
| 10 | Ph | n-Bu | 92 | >20:1 | 78 |
| 11 | n-Hex | Ph | 69 | 13:1 | 75 |
| 12 | n-Hex | Me | 80 | >20:1 | 71 |
All data are the average of two runs.
a
Isolated yield of the trans diastereomer.
b
The product was hydrolyzed and then acetylated, prior to isolation.