Substrate scope of cyclic 1-azadienes 1a.
| ||||
|---|---|---|---|---|
| Entry | R1 in 1 | 3 | Yieldb (%) | drc |
| 1 | 2-FC6H4 (1b) | 3ba | 85 | >20 : 1 |
| 2 | 3-FC6H4 (1c) | 3ca | 90 | >20 : 1 |
| 3 | 4-FC6H4 (1d) | 3da | 85 | >20 : 1 |
| 4 | 3-ClC6H4 (1e) | 3ea | 86 | >20 : 1 |
| 5 | 4-ClC6H4 (1f) | 3fa | 80 | >20 : 1 |
| 6 | 3-BrC6H4 (1g) | 3ga | 79 | >20 : 1 |
| 7 | 4-BrC6H4 (1h) | 3ha | 80 | >20 : 1 |
| 8 | 4-CNC6H4 (1i) | 3ia | 75 | >20 : 1 |
| 9 | 2-MeC6H4 (1j) | 3ja | 79 | >20 : 1 |
| 10 | 3-MeC6H4 (1k) | 3ka | 76 | >20 : 1 |
| 11 | 4-MeC6H4 (1l) | 3la | 73 | >20 : 1 |
| 12 | 2-OMeC6H4 (1m) | 3ma | 67 | >20 : 1 |
| 13 | 3-OMeC6H4 (1n) | 3na | 75 | >20 : 1 |
| 14 | 4-OMeC6H4 (1o) | 3oa | 77 | >20 : 1 |
| 15 | 2-Naphthyl (1p) | 3pa | 72 | >20 : 1 |
| 16 | 2-Thienyl (1q) | 3qa | 74 | >20 : 1 |
a
Reactions were carried out with 1 (0.1 mmol), 2a (0.12 mmol), and DBU (20 mol%) in 2 mL of THF at rt for 12–48 h.
b
Isolated yields.
c
Determined by 1H NMR.