Hydroformylation of Styrene Catalyzed by [RhH₂(Ph₂N₃) (PPh₃)₂] in Dimethyl Sulfoxide

Abstract

The homogeneous hydroformylation of styrene catalyzed by dihydridorhodium complex [RhH₂ (Ph₂N₃) (PPh₃)₂] with synthesis gas (CO/H₂O = 1/1) was carried out in dimethyl sulfoxide. The synthesis gas pressure was in the range from 9.8×10⁴ to 9.8×10⁵ Pa, and the temperature was changed from 303to 333 K. The products were 2- and 3-phenylpropanal, 2-phenylpropanal being more abundant. Increase in the pressure of synthesis gas and addition of 1, 3-diphenyltriazene or triphenylphosphine increased the yield of 2-phenylpropanal and decreased 3-phenylpropanal. When the reaction temperature was raised, 2-phenylpropanal yield reached maximum at 323 K, and then it decreased gradually. On the other hand, the formation rate of 3-phenylpropanal was accelerated by elevating the reaction temperature. The mechanism of hydroformylation reaction was discussed.