Synthesis of Fine Chemicals and Other Products

Poliakoff et al. introduced the supercritical phase to the Friedel-Crafts alkylation reaction by using SCCO2 or by making propene, one of the reactants, the supercritical fluid [56]. This heterogeneous supercritical phase reaction was conducted continuously and the selectivity was very high if a solid acid Deloxan catalyst was utilized. 

Vieville et al. conducted the esterification of oleic acid with methanol in SCCO2 using a cation exchange resin [57]. They reported ester yields of about 50% for reactions at 40 °C and 160 as shown in eq (4.8-1). They also found that the reaction rate was limited by transportation of the reactants to the external surface of the resin. 

Catalyzed reactions between supercritical water and quinoline were studied by Li et al. [59] as a possible approach to removing nitrogen from organic compounds. The reaction of quinoline with supercritical water was hetero- 

Hybrid catalysts derived from cocondensation of Group 8 metal-chloro complexes with Si(OEt)4 via a sol-gel process were highly active for the synthesis of A/,iV-dimethyIformamide from CO2, H2 and dimethylamine under supercritical conditions, affording turnover numbers up to 100800 at 100% selectivity [61]. The activity of the catalysts, containing methylphosphine ligands, decreased in the order Ru Ir Pt,Pd Rh. It seemed that the high activity of silica matrix stabilized ruthenium complexes was due to the formation of an active hydride intermediate by hydrogenolysis of the Ru-Cl bond. 

Bertucco et al. investigated the effect of SCCO2 on the hydrogenation of unsaturated ketones catalyzed by a supported Pd catalyst, by using a modified intemal-recycle Berty-type reactor [63]. A kinetic model was developed to interpret the experimental results. To apply this model to the multiphase reaction system, the calculation of high-pressure phase equilibria was required. A Peng-Robinson equation of state with mixture parameters tuned by experimental binary data provided a satisfactory interpretation of all binary and ternary vapor-liquid equilibrium data available and was extended to multicomponent 

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