Nonpolar biphasic Suzuki reaction for the synthesis of 1-biphenyl-4-yl-ethanone

2 NONPOLAR BIPHASIC SUZUKI REACTION FOR THE SYNTHESIS OF 1-BIPHENYL-4-YL-ETHANONE 

In a Schlenk tube Pd(OAc)2 and phosphinated polymer were added to cyclohexane. After addition of K3PO4 (potassium phosphate), phenyl boronic acid, 4-bromoacetophenone and nitromethane the catalyst is formed and the reaction was stirred at 70 °C till completion (6 hours) under nitrogen. 

After cooling to room temperature, the nitromethane solvent was separated, evaporated and the remaining crude product purified by column chromatography (silica, cyclohexane/ethyl acetate), to obtain pure 1-biphenyl-4-yl-ethanone (yield 94%). 

The catalyst can be recycled at least five times by the addition of fresh nitromethane, K3PO4 and the two substrates to the catalyst phase and stirring the reaction at 70 °C for 6 hours in each cycle. The overall product yield was 95%. 

Note The method was also used for the coupling of bromobenzene (92%, 14 hours), 4-bromoanisole (90%, 14 hours), 4-chloroacetophenone (83%, 24 hours) with phenyl boronic acid. 

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