| In this thesis, the selective hydrogenation of avermectin to ivermectin was studied by employing RhCl3H2O and TPPDS(disodium salts of m-disulfonated triphenylphosphine) as catalyst in aqueous-organic biphasic system. The effects of the various reaction conditions on catalytic activity and selectivity were investigated. The reactions were performed at a temperature between 60℃ and 90℃, a pressure between 0.5 and 4MPa, and a molar ratio of RhCl3.HO and TPPDS between 1:3 and 1:10, a satisfied results could be obtained. The (C2H5)3N was introduced into the reaction system, the activity of the hydrogenation could be greatly improved. The addition of the positive ion surfactants was facilitated to effective touching catalyst with substrate in two phases, so that the reaction of hydrogenation was markedly promoted. The molecular structure of surfactant plays a key role to increase the rate of reaction. A surfactant with a big head of the positive ion and a long alkyl chain is very effect to accelerate the catalytic reaction, such as TBAC. Geminis contains two big heads of the positive ions and two long alkyl chains, it is also the most effective surfactant among the used surfactants. Under the optimum reaction conditions, e.g. Reaction temperature of 90℃, hydrogen pressure of 3.0MPa, Rhodium concentration of 4.86×10-3mol/L, and TBAC of 1.19×10-2mol/L, the conversion ofavermectin was almost completion and the selectivity was up to 90%.The new catalyst formed by the reaction BISBIS and [RhCl(COD)]2 in situ was further investigated in aqueous-organic biphasic system. Being compared with RhCl3.3H2O and TPPDS, the conversion of avermectin can reach to 97.9% and the selectiving of ivermectin is 13.8% at the same reaction conditions. The new rhodium-BISBIS catalyst exhibits a high activity, but the selectivity is much lower because the complex with nine-members chelating ring formed by the reaction of BISBIS and [RhCl(COD)]2 is not very stable.
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