Direct and Catalytic C-Glycosylation of Arenes: Expeditious Synthesis of the Remdesivir Nucleoside

Since early 2020, scientists have strived to find an effective solution to fight SARS-CoV-2, especially by developing reliable vaccines that inhibit the spread of the disease and repurposing drugs for combatting its effects on the human body. The antiviral prodrug remdesivir is still the most widely used therapeutic during the early stage of the infection. However, the current synthetic routes rely on the use of protecting groups, air-sensitive reagents, and cryogenic conditions, impeding the cost-efficient supply to patients. We therefore focused on the development of a straightforward, direct addition of (hetero)arenes to unprotected sugars. Here we report a silylium-catalyzed and completely stereoselective C-glycosidation that initially yields the open-chain polyols, which can be selectively cyclized to provide either the kinetic alpha-furanose or the thermodynamically favored beta-anomer. The method significantly expedites the synthesis of remdesivir precursor GS-441524 after subsequent Mn-catalyzed C–H oxidation and deoxycyanation.