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 via 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.