Nitrogen-directed C–H borylation catalyzed by polysaccharide-stabilized ruthenium nanoparticles

Abstract Polysaccharide-supported ruthenium catalysts (Ru/polysaccharide) efficiently promoted the regioselective C–H borylation of diverse N(sp2)-containing substrates. Ru/cellulose was highly active for aromatic C(sp2)–H borylation, whereas Ru/chitin preferentially functionalized aliphatic C(sp3)–H bonds. These catalysts were readily prepared from commercially available polysaccharides and ruthenium(III) chloride, providing stable sources of Ru(0) species. The Ru/polysaccharide prepared in this manner may serve as a precursor that gradually releases catalytically competent ruthenium nanoparticles into solution.