Journal of Physical Chemistry A, Vol.114, No.11, 3932-3938, 2010
Combining Homogeneous Catalysis with Heterogeneous Separation using Tunable Solvent Systems
Tunable Solvent systems couple homogenous catalytic reactions to heterogeneous catalytic, thereby, multiple unit Operations into I single step and Subsequently reducing waste generation and improving economics. In addition, tunable solvents can require less energy than traditional separations. Such as distillation. We extend the impact of such solvents by reporting on the application of two previously described carbon dioxide tunable solvent systems: polyethylene glycol (PEG)/organic tunable solvents (POTS) and organic/aqueous tunable solvents (OATS). In particular, we studied: (1) the palladium catalyzed carbon-oxygen Coupling of 1-bromo-3,5-dimethylbenzene and o-cresol to potassium hydroxide to produce o-tolyl-3,5-xylyl ether and 1-bromo-3,5-di-tert-butylbenzene to potassium hydroxide to produce 3,5-di-tert-butylphenol in PEG400/1,4-dioxane/water and (2) the rhodium-catalyzed hydroformylation of p-methylstyrene in water/acetonitrile to form 2-(p-tolyl) propanal, In addition, we introduce a novel tunable solvent system based oil a modified OATS where propane replaces carbon dioxide. This represents the first use of propane in a tunable solvent system.