Cp*Ir(III)-Catalyzed Stereospecific Synthesis of N-Glycosides from C-Glycosides.

This study developed a protocol for the Cp*Ir(III)-catalyzed synthesis of N-glycosides featuring carbamoimide and carbamate motifs. The developed methodology offered notable advantages, including mild reaction conditions, high efficiency, a broad substrate scope, and excellent functional group tolerance. Importantly, it preserved the stereochemical integrity of dioxazolone glycosyl reagents utilized as starting materials. The primary mechanistic investigation confirmed that the Cp*Ir(III) catalyst facilitates the in situ production of isocyanate from dioxazolone, and then it undergoes nucleophilic addition with benzamides/alkyl imides and alcohols/phenols, thereby enabling the synthesis of N-glycosyl carbamoimide and carbamate derivatives through a one-pot reaction conducted under mild conditions. Furthermore, this approach can be applied to prepare structurally complex drugs and natural products.