I&EC 75

In order to enjoy the benefits of homogeneous reactions with heterogeneous 
separations, we have designed novel solvent systems called Organic-Aqueous
Tunable Systems (OATS).  Adding CO2 to a miscible water-organic system, 
such as THF and water, will cause a phase split since the addition of CO2 
to THF increases the hydrophobicity of the THF.  Hydrophobic reactants 
and a hydrophilic catalyst can be dissolved in one aqueous-organic solution.  
Once the reaction has been run homogeneously, CO2 pressure can be used to 
split the water from the organic phase allowing for an easy separation of 
product and catalyst.  The water and catalyst can now be easily recycled.  
This technique can be used with existing aqueous biphasic reactions to 
eliminate any mass transfer limitations; similar systems are also 
applicable for biocatalysis in order to bring substrates into intimate 
contact with the enzyme catalyst.