Frustrated Lewis Acid-Catalyzed C-N Coupling for the Stereoselective Synthesis of Nucleoside Analogs.

β-N-glycosides serve as essential building blocks for constructing nucleic acid residues, and their altered forms are ubiquitous among many natural products and pharmacophores. However, the most commonly employed N-glycosylation procedures still require aggressive Lewis acid catalysts, multistep procedures to glycosyl donors, or precious metal catalysts to obviate typical catalyst quenching from basic N-nucleophiles. Here, we report a straightforward FLP-based catalytic approach for forming β-N-glycosides, emphasizing efficiency and mild conditions. We show that catalytic quantities of BCF can facilitate stereoselective N-glycosylations, coupling common pyran- and furan-based donors with various silylated N-heterocycles. The straightforward application of our N-glycosylation procedure to relevant medicinal targets was additionally shown and bodes well for the broad application of this method.