Table 2.
Examination of the influence of the grinding auxiliary on the reaction outcomea.
| Entry | Grinding auxiliary | Weight (g) | Yield (%) 3aa/4a |
| 1 | — | — | 10/trace |
| 2 | silica gel | 5.0 | 53/19 |
| 3 | NaBr | 10.0 | 69/trace |
| 4 | NaBr | 5.0 | 65/trace |
| 5 | KBr | 5.0 | 63/trace |
| 6 | NaCl | 5.0 | 27/5 |
| 7 | γ-Al2O3 (neutral) | 5.0 | 20/6 |
| 8 | sand | 5.0 | 30/10 |
aInfluence of the grinding auxiliary on the Heck reaction: 1a (1.5 mmol), 2a (2.25 mmol), Pd(OAc)2 (5 mol %), PPh3 (10 mol %), TEA (1.8 mmol), TBAB (5 mol %), and grinding auxiliary were placed in an 80 mL stainless steel vessel along with 173 stainless-steel balls (dMB = 6 mm, ФMB = 0.245), milling at 800 rpm for 90 min.