Hydroformylation Of Dicyclopentadiene Catalyzed By Thermoregulated Phosphine Rhodium Complex

Thermoregulated phase-transfer catalysis(TRPTC) has been successfully applied in the hydroformylation of higher olefins.It not only gives a new way to fundamentally solve the problem of rather low hydroformylation catalytic activity in an aqueous/organic biphasic system caused by insolubility or poor solubility of higher olefins,but also provides a promising avenue for recycling of noble metal catalytics.Based on the existing work,in this paper a nonionic phosphine ligand L[CH3(OCH2CH2nPPh2(n?16)] with thermoregulation function has been synthesized and the structure has been characterized through NMR technique.In this study,rhodium complex formed in situ by Rh(CO)2(acac) with thermoregulated phosphine has been used as catalyst for hydroformylation of Dicyclopentadiene(DCPD) in aqueous/organic biphasic system.The influences of temperature,pressure of synthesis gas,reaction time,molar ratios of substrate/catalyst and other factors on hydroformylation of DCPD to synthesis tricyclodecanemonoaldehyde(TCDMA) and tricyclodecanedialdehyde (TCDDA) have been tested and discussed in detail.Research shows that under the optimal reaction conditions(S/Cat= 1000,P/Rh= 8,t= 45 min,P= 3 MPa(H2/CO= 1),T= 90?),the conversion of DCPD and the yield of aldehyde were 99.3% and 98.7%,respectively.The product mainly consisted of TCDMA,and the selectivity reached up to 97.6%, TOF is 1301 h-1.The catalyst dissolved in the aqueous phase could be easily recovered by phase simple separation,and can be recycled 5 times without obvious decline in activity.Both the yield of aldehyde and the selectivity of TCDMA were still above 91%.The average leaching of rhodium was 0.6 wt% in organic phase in the previous four recycles.Based on the study of DCPD hydroformylation to synthesis TCDMA,under the optimized conditions(T= 110?,P/Rh= 4,S/Rh= 1000(molar ratio),P= 6 MPa(CO/H2= 1),t = 4.0 h),DCPD was almost converted to aldehydes,the major product was TCDDA,and the selectivity were 97.1%.The catalyst can be recycled 4 times without obvious decline in activity,the selectivity of aldehyde and TCDDA still above 96% and 79%,respectively.The average leaching of rhodium was 1.4 wt% while recycling the catalyst.