Phosphorus-containing compounds are ubiquitous throughout both industrial and academic chemistry, with myriad uses that range from pyrotechnics to flame retardants and from fumigants to pharmaceuticals. Unfortunately, in all cases the synthesis of these products relies on the use of white phosphorus (P₄) as the ultimate P atom source. This is extremely undesirable: P₄ is both toxic and notoriously pyrophoric, and its preparation via electric arc furnace reduction of phosphate is so hazardous that it is no longer performed anywhere in Europe. This project will therefore target the selective, partial reduction of molecular phosphate compounds directly to useful products, without the intermediacy of P₄. Specifically, the project will target the synthesis of phosphites via reduction of molecular species such as tetra(alkoxy)phosphonium cations and phosphate-derived acid anhydrides, which are known to be accessible from phosphate starting materials.

Enzymes are already becoming established, alongside chemical catalysts, to help with steps in the production of fine chemicals such as pharmaceuticals and flavour-fragrance molecules. They are particularly valuable for reduction of double bonds where a chiral product is desired, including C=O, C=C and C=N bonds. Although enzymes offer impressive selectivity for a given functional group in a molecule, they are often expensive to operate because they depend on costly cofactors, NADH or NADPH, which must be recycled, often with glucose as a carbon-intensive reductant. We have established cleaner methods for running biocatalysis, using hydrogen gas as a reductant. We also immobilise enzymes on carbon supports so that they can be used interchangeably with supported metal catalysts for hydrogenation reactions. This project will implement hydrogen-driven biocatalytic methods for making amine products and amino acids. Reactions will be run on a small scale under a mild hydrogen atmosphere, and products will be analysed by NMR, gas chromatography (GC) and HPLC.