Table 5. Scope of Indole Annulation.
entry | pyrrole | R2 | R3 | R6 | indole | time (h) | yield (%) |
---|---|---|---|---|---|---|---|
1 | 2a | –H | –H | –H | 3a | 12 | 91 |
2 | 2b | –Br | –H | –H | 3b | 12 | 67 |
3 | 2c | –CO2Et | –H | –H | 3c | 12 | 62 |
4 | 2d | –Ph | –H | –H | 3d | 12 | 87 |
5 | 2e | –H | –CH3 | –H | 3e | 12 | 94 |
6 | 2f | –H | –CH2CH3 | –H | 3f | 12 | 92 |
7 | 2g | –H | –Br | –H | 3g | 12 | 75 |
8 | 4a | –H | –H | –CH3 | 5a | 8 | 88 |
9 | 4b | –H | –H | –CH2CH3 | 5b | 8 | 95 |
10 | 4c | –H | –H | –CH2Ph | 5c | 8 | 96 |
11 | 4d | –H | –H | –CH2CH=CH2 | 5d | 8 | 93 |
12 | 4e | –H | –H | –CH2C≡CH | 5e | 8 | 92 |
13 | 4f | –H | –H | –CH2CO2Et | 5f | 8 | 72 |