Multiphase catalysis in temperature-dependent multi-component solvent (TMS) systems

Abstract

The use of temperature-dependent multi-component solvent-systems (TMS) as a new recycling concept was investigated. The temperature dependency of the solvent systems and suitable compositions for various reactions were determined by cloud titrations. The results were summarized in an expert system for the solvent selection. Appropriate thermomorphic solvent systems were applied to different C-C bond-forming reactions: the telomerization of butadiene with ethylene glycol or with carbon dioxide, the isomerizing hydroformylation of trans-4-octene and the hydroaminomethylation of 1-octene with morpholine. In further investigations the carboxytelomerization and the synthesis of 4-nitrodiphenylamine were examined. Especially, if the polarity of the reaction mixture remains constant, high conversions of the substrates and high selectivities can be achieved. Thus, for the hydroformylation the conversion reaches a level of 99% and a selectivity to n-nonanal of about 80% in the TMS system propylene carbonate (PC)/dodecane/ N-methylpyrrolidone (NMP). Similar results are obtained for the hydroaminomethylation: if N-octylpyrrolidone is used as a mediator the conversion of 1-octene and the selectivity of the corresponding amines reach 92%. For both reactions the catalyst can be easily recovered by a simple phase separation with only marginal loss of rhodium catalyst. © 2006 Springer-Verlag Berlin Heidelberg.