Synthesis of 3- diphenylphosphino -4-methyl-styrene

Magnesium (0.72 g, 30 mmol) was added into a 50-mL round-bottomed flask, which was dried and filled with nitrogen. Dry tetrahydrofuran (THF) (10 mL) was injected first and then stirred with the magnesium. Half the solution of 3-bromo-4-methyl-styrene (3.94 g, 20 mmol) in dry THF (10 mL) was injected dropwise. After the exothermic reaction started, the rest of the solution was injected. 

The Grignard reagent was added into the mixture of chlorodiphenylphosphine (5.25 g, 25 mmol) in dry THF (10 mL) at 0 °C. After completion of the addition, the temperature was raised to the room temperature. 

After stirring for another 20 hours, the mixture was poured into a saturated aqueous ammonium chloride solution (10 mL) at 0°C and extracted with dry THF (3 x 20 mL). The organic layer was dried over anhydrous magnesium sulfate and concentrated to 5 mL. Hexane was added into the organic solution to deposit the by-products. 

METAL CATALYSED CARBON-CARBON BOND-FORMING REACTIONS 

After filtration and concentration, the residue was purified by a flash column chromatography (hexane/EAC = 4/1). The isolated product was 2.42 g (39% yield). 

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