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. Author manuscript; available in PMC: 2008 Dec 10.
Published in final edited form as: Tetrahedron Lett. 2007 Dec 10;48(50):8811–8814. doi: 10.1016/j.tetlet.2007.10.078

Table 2.

Optimization of coupling reaction between enaminone 1a and 4-methoxyphenylboronic acid.a

Entry Base Solvent(s), Temperature Reaction Time Yield %b
1 CaCO3 DMF/H2O (3/1), 150 °C 20 h 0
2 Na2CO3 DME/H2O (1/1), 100 °C 20 h 13
3 Na2CO3 toluene, 110 °C 20 h 23
4 Na2CO3 toluene/EtOH (1/1), 110 °C 20 h 25
5 CsF MeCN/H2O (1/1), 100 °C 14 h 27
6 Ba(OH)2 dioxane/H2O (3/1), 110 °C 14 h 65
7c Ba(OH)2 dioxane/H2O (3/1), 150 °C MWc 15 min 70
a

Compound 1a (0.10 mmol) was dissolved in degassed solvent mixture (0.25–0.5 M) under argon and 4-methoxyphenylboronic acid (0.17 mmol), base (0.20 mmol) and Pd(PPh3)4 (0.02 mmol) added.

b

Isolated yield.

c

Carried out employing microwave irradiation (150 °C, 15 min).