N–Si Heterolysis by Chiral (BOX)Cu(OTf)2 Catalysts for the Synthesis of Indole and Carbazole Glycosides

Chiral Cu(II) bisoxazolines have been shown to catalyze the coupling of acetyl-protected carbohydrates with N-silylated indoles to give the corresponding N-glycosides. Preliminary mechanistic experiments indicated that catalysis occurs through formation of a Cu-indolide complex with concomitant formation of TMS-OTf which together activate the sugar and deliver the indole nucleophile.