W₁/TiO_{2- x} Enabled Photoelectrochemical Tandem Upgrading of Glycerol to Nucleoside Precursors

Pentose aminooxazoline (PAO) is a key precursor in the synthesis of nucleoside and carbohydrate drugs. However, conventional PAO synthesis methods are hindered by slow reaction rates, low yield, and instability of raw material glyceraldehyde (GLD). Herein, we report a highly efficient photoelectrochemical tandem synthetic pathway that overcomes the fundamental limitations. Using biomass-derived glycerol as the feedstock, we achieve highly selective in situ photoelectrosynthesis of GLD on a defective TiO₂ photoanode decorated with W single-atom (W₁/TiO_2-x). Importantly, this photoanode enhances the stability of in situ generated GLD, beneficial to its tandem addition reaction with 2-aminooxazole (2-AO) for PAO synthesis. Under optimized conditions, the system delivers a PAO yield of 3.72 µmol h^-1 cm^-2, 54-fold enhancement over the conventional method. We demonstrate the synergistic interaction between oxygen vacancies and W single-atom not only preserves the C-C bond to ensure the high selectivity of GLD but also significantly enhances the electrophilicity of carbonyl carbon in GLD. This greatly improves the addition reaction between 2-AO and in situ generated GLD toward PAO yield. This work provides a green, efficient, and scalable strategy for PAO synthesis, fundamentally addressing the long-standing challenges of feedstock instability and low yield associated with traditional methods.