Table 1.
| ||||
---|---|---|---|---|
Entry | Additive | Substrate: 1a | 1b | |
Yield of 2 (%)a | ||||
1 | none | 28 | 52 | |
2 | 16 | 39 | ||
3 | 44 | 59 | ||
4 | /TsOH (0%) | 24 | 53 | |
5 | /TsOH (12%) | 79 | 74 | |
6 | /TsOH (0%) | 45 | 98 | |
7 | /TsOH (6%) | 48 | 95 | |
8 | /TsOH (12%) | 50 | 81 | |
9 | /TsOH (0%) | 45 | 78 | |
10 | /TsOH (6%) | 50 | 90 | |
11 | /TsOH (12%) | 57 | 86 | |
12 | Pd/C instead of Pd(TFA)2 | 1 | < 2 | |
13 | Pd/Al2O3 instead of Pd(TFA)2 | 0 | < 1 |
Entries 1–5, 12, and 13 obtained from reference 3a.