Photocatalytic Achmatowicz Rearrangement on Triphenylbenzene-Dimethoxyterephthaldehyde-Covalent Organic Framework-Mo for Converting Biomass-Derived Furfuryl Alcohol to Hydropyranone.

Abstract

The conversion of biomass-based feedstocks into high-value platform compounds remains a fundamental but challenging topic. Studies on such transformations are sparse due to the complex nature of biomass and limited upgrading strategies. Photocatalytic aerobic oxidation is a promising pathway for making pharmaceutical precursors from biomass-derived chemicals. In this study, we demonstrate the transformation of furfuryl alcohol into dihydropyranone acetyl by using a molybdenum-incorporated triphenylbenzene-dimethoxyterephthaldehyde-covalent organic framework <i>via</i> a singlet oxygen (¹O₂)-mediated photocatalytic Achmatowicz reaction. The COF-Mo photocatalyst exhibits exceptional selectivity up to 98% in producing hydroxy-2H-pyran-3(6H)-one, a complex synthone crucial for synthesizing anti-AIDS drugs. Mo incorporation enhances the generation rate by 3.9 times, primarily due to the synergistic effect between Mo active sites and the COF backbone. More importantly, Mo clusters create a superfast charge tunnel for photogenerated electron transfer from COF to adsorbed O₂. The metallic state and hexavalent of Mo facilitate the generation of superoxide anions and ¹O₂, respectively, facilitating photocatalytic reactions.