Professor Nicole Grobert, Ceren Zor and colleagues from the Department of Chemistry in Oxford have developed a new method for combining chemo and biocatalysis on carbon supports.
Published in Chemical Science, the paper explains that heterogeneous biocatalytic hydrogenation is an attractive strategy for clean, enantioselective C=X reduction. This approach relies on enzymes powered by H2-driven NAD reduction.
Selected metal/C catalysts are then used for H2 oxidation with electrons transferred via the conductive carbon support material to an adsorbed enzyme for NAD reduction.
These chemo-bio catalysts show improved activity and selectivity for generating bioactive NADH under ambient reaction conditions compared to metal/C catalysts.
The metal/C catalysts and carbon support materials (all activated carbon or carbon black) are characterised to probe which properties potentially influence catalyst activity. The optimised chemo-bio catalysts are then used to supply NADH to an alcohol dehydrogenase for enantioselective (>99% ee) ketone reductions, leading to high cofactor turnover numbers and Pd and NAD reductase activities of 441h-1 and 2347 h-1 respectively.
This method demonstrates a new way of combining chemo and biocatalysis on carbon supports, highlighted here for selective hydrogenation reactions.