Table 3. Brønsted Acid-Catalyzed Transannular Aminohalogenation on Lactams 5a–f.
entry | R1 | R2 | R3 | compd | yield 6a–f (%)a | compd | yield 7a–f (%)a |
---|---|---|---|---|---|---|---|
1 | H | H | H | 6a | 98 (40 min) | 7a | 86 (16 h) |
2 | H | F | H | 6b | 98 (60 min) | 7b | 86 (16 h) |
3 | H | H | F | 6c | 68 (60 min) | 7c | 81 (16 h) |
4 | H | H | MeO | 6db | 41 (21 h) | 7d | 71 (23 h) |
5 | H | H | Me | 6e | 79 (3 h) | 7e | 85 (16 h) |
6 | Me | H | H | 6fb | 26 (72 h) | 7f | 46c (72 h) |
Yield of pure products after flash column chromatography purification.
1.2 equiv of DBU was added after complete conversion of the starting material had been observed.
98% yield based on the recovered starting material.