Synthesis Of New Triarylphosphine Ligands And Their Application In Hydroformylation Of Styrene And Hydrogenation Of Ketone

A series of new triarylphosphine ligands 6 with long-chain alkoxy have beenprepared through five steps from commercially available 3-bromophenol by a newsynthetic route. This improved synthesis way was straightforward, quick, reliable,and gave a universal method to afford the triarylphosphine ligands with differentsubstituents. The use of the commercially available materials and simpleprovided a convenient method for preperation of triarylphosphine in large scale.The catalytic properties of phosphine 6 as ligand was studied in theRh-catalysed hydroformylation of streyene. The effect of P/Rh and reactiontemperature as well as different ligands were investigated in detail. The resultsindicated that the electron-donating alkoxy of aromatic ring induced the loweractivities and better regioselectivity than TPE Ligand 6a～6e and 6f～6j havesimilar activity, but 6f～6j have less regioselectivity than 6a～6e due to the biggersteric hindrance of 6a～6e.The asymmetric hydrogenation of acetophenone catalysed by in suti formed[Ru(6)₂Cl₂—DPEN] was studied. The result indicated that the suitabe alkali andlow reaction temperature was good for the enantioselectivity. With inceaseing the chain-length of alkoxy, the enantioselectivity was improved gradually. Theselective hydrogenation of benzylacetone catalysed [Ru(6)₂Cl₂—DPEN] was alsostudied. The results showed that the alkali played a important role in catalyticreaction and there was a optimal concentration of alkali. Influence of differentligands has been also investigated in hydrogenation of benzylacetone. The biggersteric hindrance of phosphines made higher selectivity of the hydrogenation ofC=O group.