Development of Catalysts for Asymmetric Reactions and Energy Conversion.

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The efficient production of pharmaceuticals and the storage/transformation of energy from renewable sources are fundamental, vital objectives of modern chemical research. Our first project builds on our discovery of an efficient amide hydrogenation catalyst. The reduction of amides in industry typically utilizes stoichiometric main-group hydrides. These flammable hydrides must be transported, and their use requires a dangerous, exothermic hydrolysis that generates waste. Catalytic amide hydrogenation eliminates these negatives, and Pharma has identified the development of such a reaction as a key need to reduce the costs and environmental impact of pharmaceutical production. We recently discovered that Ru(Ph2PCH2CH2NH2)2(H)2, (1) is a powerful amide hydrogenation catalyst that is over 67x more active than previous catalysts. Compound 1 hydrogenates a wide, useful variety of amides with high yields and low catalyst loadings. These hydrogenations proceed with C-N cleavage to generate the product alcohol and amine. They also require added base, which can be a limitation. We very recently developed a catalyst that operates without added base. We will begin by modifying this important catalyst to maximize its activity and to make it stable enough for convenient storage over long periods of time. We are currently developing asymmetric versions of amide hydrogenations that proceed in up to 99 % ee. Racemic amides can be hydrogenated with dynamic kinetic resolution (DKR) under extremely mild conditions (4 atm H2, room temperature). We will develop DKR reductions of racemic esters using the same methodology. Currently, there is only one example of this important type of hydrogenation in the literature, and it proceeded with low selectivity and impractical catalyst loadings. We will develop the asymmetric DKR hydrogenation of racemic amides with C-O cleavage. We already have promising early results that we will build upon to develop this important unprecedented reaction. ***The second project builds upon our development of polymerized chiral catalysts that are the most reusable to date for asymmetric ketone hydrogenations, olefin cycloisomerizations, and olefin hydrogenations in flow reactors. This system has been licensed by GreenCentre Canada and we are developing custom polymerized catalysts with Merck and Dr. Reddy's. We propose to develop new polymeric catalysts that hydrogenate esters and amides continuously in flow reactors. We will also develop magnetic supports for these catalysts so that simple magnets can be used to isolate them for reuse. ***In our third project, we have developed a simple, bench-top synthesis of the most active water oxidation catalysts known to date. We will develop these catalysts, investigate how they operate, and evaluate them in prototype water electrolyzers as part of highly efficient solar energy storage systems.**