Transition metal chemistry and catalysis

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Hydrogenation catalysts are used by industry to produce fuels, bulk chemicals and fine chemicals including pharmaceuticals, agrochemicals and fragrances. They are usually composed of expensive, rare and toxic platinum metals. Since 2007 our group has discovered and invented sustainable and much cheaper iron catalysts that promise to replace some conventional catalysts used for the asymmetric hydrogenation of ketones and imines for the production of valuable alcohols and amines. For example, certain alcohols can be used for the synthesis of drugs used in chemotherapy, and selected amines, in the synthesis of antidepressants and antibiotics. Cheap iron catalysts might also find application in the energy field in the hydrogenation of carbon dioxide as well as hydrogen storage and evolution. It is proposed to discover further useful catalyst structures and fully understand them so that this replacement process, vital for a greener chemical industry, can be successful. A variety of new, efficient syntheses are proposed that are amenable to high throughput screening of catalysts. Catalysts will be formed from novel and known modules under mild conditions where the iron ion acts as a template. A component of interest is the N-heterocyclic carbene (NHC) donor since this allows catalyst synthesis without the use of toxic phosphine reagents. We have discovered active NHC catalysts for ester hydrogenation that might make obsolete the wasteful use of boron and aluminum reductants. It is important to determine whether the catalysts are homogeneous or heterogeneous. We reported in 2012 the first example of asymmetric catalysis using iron nanoparticles that are formed from a homogeneous solution of iron precursor. We will use state of the art practical and theoretical methods to probe the functioning of our new catalyst systems. This work might also lead to the discovery of catalysts that use sunlight to split water into hydrogen fuel and oxygen and catalysts for the efficient synthesis of polyamides.