Hydroformylation And Cyclopropanation Of Alkenes In The Thermoregulated Ionic Liquid Biphasic System

Based on the thermoregulated ionic liquid biphasic system proposed by our research group,the phase diagrames of IL350-toluene-n-heptane,IL550-toluene-n-heptane and IL750-toluene-n-heptane are studied in detail.IL750-toluene-n-heptane biphasic system is selected to be the best system for its good thermoregulated character.In this thermoregulated ionic liquid biphasic system,the ligand TPPTS for the Rh/P-catalyzed hydroforrnylation of 1-dodecene is studied.It is found that when the composition is IL750:toluene: n-heptane:1-dodecene=0.5:4.23:0.5:1.0 and the miscible temperaute is 108℃,under optimum reaction conditions(S/Rh=1500(molar ratio),TPPTS/Rh =8(molar ratio),P=5.0 MPa(H₂/CO=1:1),T=110℃,t=5h) the conversion of 1-dodecene and the yield of aldehydes reach up to 98%and 96%,respectively.The catalyst can be recycled 8 times without evident loss of catalytic activity and the average Rh loss in the product phase is 0.64%.The IL750-toluene-n-heptane thermoregulated ionic biphasic system is succesfully applied in the cyclopropanation of alkenes.After studing the model reaction-cyclopropanation of styrene with ethyl diazoacetate(EDA)-in IL750,the Pd/TPPTS is selected.The activity and recycling efficiency of this catalyst for the cyclopropanation of 1-octene in the thermoregulated ionic liquid biphasic system is further studied.Under the optimized reaction conditions(1-octene:EDA=5:1(molar ratio),TPPTS/Na2PdCl₄·3H₂O =1(molar ratio),EDA:Na₂PdCl₄·3H₂O=100,T=50℃,t=7h),the yield reaches up to 65%, the catalyst can be recycled five runs without obvious decrease of activity.Based on the character that IL750 can both be dissolved in the PEG and dissolve TPPTS, IL750 is conceived to be media to realize the application of Rh/TPPTS complex for the hydroformylation of higher olefins in the thermoregulated PEG biphasic system.It is found that in the PEG200-toluene thermoregulated biphasic system,under optimum conditions,the conversion of 1-dodecene and the yield of aldehyde reach up to 96%and 94%,respectively. The catalyst,after being recycled 8 times,showes no appreciable loss of catalyst activity.The average loss of Rh loss is 0.63%.