C. de Bellefon

Application of a Micromixer for the High Troughput Screening of Fluid-Liquid Molecular Catalysis

High throughput synthesis methodologies, such as combinatorial techniques, are now applied to the discovery of molecular catalysts.1 Libraries of ligands which can be turned into catalysts by complexation to transition metals, are accessible. The effectiveness of this approach has been demonstrated for restricted libraries of compounds and in the case of single liquid phase catalysis.[2] However, numerous reactions of interest such as olefin oligomerisation, hydrogenation, carbonylation, hydroformylation, etc. are operated in gas-liquid or liquid-liquid systems. Inadequate control of phase and catalyst presentation, resulting from non-optimised agitation, may effectively have dramatic consequences in the estimation of selectivity and reactivity. For example, enantio- and regioselective catalysed reactions susceptible to mass transport effects, are known. Thus, a major challenge is to develop special reactors for rapid catalyst screening that would ensure good mass and heat transport, in a small volume. Application of such apparatus for intrinsic kinetic determination would also be of high interest. In this paper, a new concept to achieve High Throughput Screening (HTS) of polyphasic fluid reactions is proposed. As test reactions, a gas-liquid asymmetric hydrogenation and a liquid-liquid isomerisation have been chosen to validate our approach of HTS experiments. A preliminary work with the liquid-liquid system has been published recently.2