Table 1.
Ruthenium-catalyzed enyne cycloisomerizations
 | |||||
|---|---|---|---|---|---|
| entry | R1 | R2 | n | yield, time (%, h)a | drb |
| 1 | CO2Me | CO2Me | 1 | 90, 3 | > 19:1 |
| 82, 3c | > 19:1 | ||||
| 2 | CHO | CO2Me | 1 | 88, 2 | > 19:1 |
| 3 | CON(OMe)Me | CO2Me | 1 | 79, 3 | > 19:1 |
| 4 | CO2H | CO2Me | 1 | 95, 3 | > 19:1 |
| 5 | CH2OH | CO2Me | 1 | 86, 6d | > 19:1 |
| 6 | CO2Me | CO2Me | 2 | 99, 3 | > 19:1 |
| 7 | CHO | CO2Me | 2 | 87, 5e | > 19:1 |
| 8 | CON(OMe)Me | CO2Me | 2 | 99, 4 | > 19:1 |
| 9 | CO2Me | COi-Pr | 1 | 70, 6e | > 19:1 |
| 10 | CO2Me | CONEt2 | 1 | 70, 3d,f | > 19:1 |
a
Isolated yield.
b
Determined by 1H NMR.
c
Using 3 mol % catalyst.
d
Using 10 mol % catalyst.
e
Using 20 mol % catalyst.
f
Temp: 40 °C.