Table 1 Reaction optimization.a
From: Practical and regioselective halonitrooxylation of olefins to access β-halonitrates
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|---|---|---|---|---|---|---|
Entry | R | [M] | temp. (°C) | Time | Yield | rr |
1 | 4-H (1a) | – | 0 | 2 min | 82% | 3.8:1 |
2 | 4-H (1a) | FeCl3 | 0 | 2 min | 42% | >20:1 |
3 | 4-H (1a) | FeCl3 | −40 | 10 min | 76% | 16:1 |
4 | 4-Me (1b) | FeCl3 | −40 | 10 min | 54% | 16:1 |
5 | 4-F (1c) | FeCl3 | −40 | 1 h | 55% | >20:1 |
6 | 4-CF3 (1d) | FeCl3 | −40 | 2 h | 83% | >20:1 |
7 | 4-CN (1e) | FeCl3 | −40 | 8 h | 50% | 15:1 |
8 | 4-NO2 (1f) | FeCl3 | −40 | 12 h | 10% | 15:1 |
9 | 2-Me,4-NO2 (1g) | FeCl3 | −40 | 3 h | 56% | 5:1 |
10 | 3,5-di-F (1h) | FeCl3 | −40 | 1 h | 74% | 12:1 |
11 | 2,6-di-F (1i) | FeCl3 | −40 | 1 h | 90% | 3:1 |
12 | 2,4-di-F (1j) | FeCl3 | −40 | 1 h | 56% | 4:1 |
13 | 3,4-di-F (1k) | FeCl3 | −40 | 1 h | 71% | 7:1 |
14 | 3,4,5-tri-F (1l) | FeCl3 | −40 | 1 h | 65% | 12:1 |
15 | 3-CF3 (1m) | FeCl3 | −40 | 2 h | 56% | 7:1 |
16 | 2-CF3 (1n) | FeCl3 | −40 | 2 h | 72% | 3:1 |
17 | 3,5-di-CF3 (1o) | FeCl3 | −40 | 2 h | 45% | 7:1 |
18b | 4-CF3 (1d) | FeCl3 | −40 | 2 h | 82% | >20:1 |
