chapter 2 palladium catalysts in suzuki cross- coupling reaction
chapter 2 palladium catalysts in suzuki cross- coupling reaction
chapter 2 palladium catalysts in suzuki cross- coupling reaction
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Table 5.1. The effect of additive, temperature and DMA: water ratio on Pd-NaY<br />
H 3COC<br />
catalyzed Suzuki <strong>reaction</strong> of 4-chloroacetophenone over the Pd concentration<br />
of 0.68% a<br />
Cl B(OH) 2<br />
+<br />
1 mmol 1.2 mmol<br />
30 m<strong>in</strong>, <strong>in</strong><br />
N 2<br />
2 mmol base,<br />
0.5 mmol Bu 4NBr<br />
10 mL DMA<br />
Entry T (°C) Bu4NBr Conversion% b Yield% b<br />
1 140 - 49 36<br />
2 140 + 54 46<br />
3 c 140 + 20 14<br />
4 160 + 70 57<br />
a PhB(OH)2 was supplied from Aldrich. b GC yield. c Performed <strong>in</strong> a<br />
sealed glass reactor and <strong>in</strong> a DMA/water solvent mixture (9:1).<br />
COCH 3<br />
Under the def<strong>in</strong>ed conditions (Table 5.1, entry 4), the effect of base type on the<br />
<strong>reaction</strong> efficiency was also screened. Table 5.2. shows that alkoxides (entries 5-7) are<br />
more effective than the carbonates (entries 1-3), K3PO4 (entry 4) and hydroxides (entries<br />
8-10). As a result, NaOC2H5 was chosen as optimal base for activation of Suzuki<br />
<strong>reaction</strong> (Table 5.2, entry 5).<br />
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