Synthesis of N,N-dimethylformamide from carbon dioxide in aqueous biphasic solvent systems

This paper presents the homogeneous catalyzed hydrogenation of carbon dioxide to N,N-dimethylformamide (DMF) with an in-situ generated ruthenium catalyst based on RuCl3 x H2O and the phosphine ligand 2,2'-bis(diphenylphosphinomethyl)-1,1'-biphenyl (BISBI). Investigations showed that the complex formation of an active species requires the presence of an amine. The catalyst was recycled by immobilization in a nonpolar alcoholic solvent while the formed product was extracted in-situ into the aqueous phase. The self-assembling reaction system showed stability for 10 recycling runs without a significant loss of activity resulting in an average yield of 31% DMF at 40 bar and 140 degrees C without the occurrence of any byproducts. Furthermore, a combination of the developed reaction system with ternary amines enables the application of wash amine solutions as carbon dioxide carrier. (C) 2017 Elsevier B.V. All rights reserved.