Table 2.
Tandem deprotection–aldol reaction[a]
| Entry | Catalyst | Substrate | Conversion [%] | Yield GC/isolated [%] | |
|---|---|---|---|---|---|
| 2 | 4 | ||||
| 1 | SAB[b] | 1 | >98 | tr | 99/91 |
| 2 | SB | 1 | – | – | –/– |
| 3 | SAB[c] | 1 | ≈99 | ≈95/– | 5/– |
| 4 | SB[e] | 2 | >99 | – | >99/92 |
| 5 | S | 1 | tr | tr | tr |
| 6 | SAB[d] | 1 | 95 | tr | ≈95/91 |
[a]
Reaction conditions: benzaldehyde dimethyl acetal (1 mmol), CH2(CN)2 (10 mL), 50 °C, 12 h.
[b]
HPW/AP ratio around 0.5:1 (molar).
[c]
HPW/AP ratio around 1:1 (molar).
[d]
Fourth recycle of the catalyst in entry 1.
[e]
For the aldol reaction alone starting from 2. tr: trace.