Table 1.
Entry |
DABCO [equiv] |
Conversion of 2 a [%][b] |
Yield of 3 a [%][b] |
---|---|---|---|
1 |
0 |
22 |
20 |
2 |
1.10 |
>95 |
60 |
3 |
0.55 |
88 |
43 |
4 |
0.10 |
26 |
15 |
5[c] |
0.10 |
23 |
17 |
6[d] |
0.55 |
>95 |
0 |
[a] Performed at room temperature for 20 min. [b] Determined by 19F qNMR with 3,3′‐bis(trifluoromethyl)benzophenone as internal standard. [c] Use of CaCO3 (1.10 equiv) in addition to DABCO. [d] Performed at 60 °C. DABCO=1,4‐diazabicyclo[2.2.2]octane, THF=tetrahydrofuran.