Continuous Flow Hydroformylation of Alkenes in Supercritical Fluid-Ionic Liquid Biphasic Systems was written by Webb, Paul B.;Sellin, Murielle F.;Kunene, Thulani E.;Williamson, Sylvia;Slawin, Alexandra M. Z.;Cole-Hamilton, David J.. And the article was included in Journal of the American Chemical Society in 2003.Electric Literature of C7H13ClN2 This article mentions the following:
A process for the hydroformylation of relatively low volatility alkenes (demonstrated for 1-dodecene) in a continuous flow system is described. The catalyst is dissolved in an ionic liquid while the substrate and gaseous reagents are transported into the reactor dissolved in supercritical CO2, which simultaneously acts as a transport vector for aldehyde products. Decompression of the fluid mixture downstream yields products which are free of both reaction solvent and catalyst. The use of rhodium complexes of triaryl phosphites as catalysts leads to ligand degradation through reaction of the ionic liquid with water and subsequent attack of the released HF on the phosphite. Sodium salts of sulfonated phosphines are insufficiently soluble in the ionic liquids to obtain acceptable rates, but replacing the sodium by a cation similar to that derived from the ionic liquid, allows good solubility and activity to be obtained. The nature of the ionic liquid is important in achieving high rates, with 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amides giving the best activity if the alkyl chain is at least C8. Catalyst turnover frequency as high as 500 h-1 was observed, with the better rate at higher substrate flow rate. Rhodium leaching into the product stream can be as low as 0.012 ppm, except at low partial pressures of CO/H2, when it is significantly higher. Oxygen impurities in the CO2 feed can lead to oxidation of the phosphine giving higher rates, lower selectivity to the linear aldehyde, increased alkene isomerization, and greater leaching of rhodium. However, under certain process conditions, the supercritical fluid-ionic liquid (SCF-IL) system can be operated continuously for several weeks without any visible sign of catalyst degradation Comparisons with com. hydroformylation processes are provided. In the experiment, the researchers used many compounds, for example, 1-Methyl-3-propylimidazolium Chloride (cas: 79917-89-8Electric Literature of C7H13ClN2).
1-Methyl-3-propylimidazolium Chloride (cas: 79917-89-8) belongs to imidazole derivatives. Imidazole is a heterocyclic compound with a five-membered planar ring. It is amphoteric and highly polar. Imidazole based anticancer drug find applications in cancer chemotherapy. It is used as buffer component for purification of the histidine tagged recombinant proteins in immobilized metal-affinity chromatography (IMAC).Electric Literature of C7H13ClN2
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem