Aqueous Biphasic Systems for the Synthesis of Formates by Catalytic CO Hydrogenation: Integrated Reaction and Catalyst Separation for CO -Scrubbing Solutions.

Aqueous biphasic systems were investigated for the production of formate-amine adducts by metal-catalyzed CO hydrogenation, including typical scrubbing solutions as feedstocks. Different hydrophobic organic solvents and ionic liquids could be employed as the stationary phase for cis-[Ru(dppm) Cl ] (dppm=bis-diphenylphosphinomethane) as prototypical catalyst without any modification or tagging of the complex. The amines were found to partition between the two phases depending on their structure, whereas the formate-amine adducts were nearly quantitatively extracted into the aqueous phase, providing a favorable phase behavior for the envisaged integrated reaction/separation sequence.