In(OTf)3-Only-Catalyzed Glycosylation via Activation of an Alkyne Appended with an Amide Auxiliary Group
Liya Yang1, Yanli Qiu1, Lingyun Pan2
1Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Abstract:
We herein present the development of a novel glycosylation protocol using glycosyl o-N-(o-methoxybenzamidoyl)-propynyl benzoates as donors, activated solely by a catalytic amount of In(OTf)3, eliminating the need for a Au(I) catalyst. This approach offers mild and orthogonal conditions, enabling glycosylation across a broad substrate scope and facilitating versatile one-pot strategies for glycan assembly. Mechanistic insights suggest that In(OTf)3 serves dual roles by being recruited to the auxiliary group through σ-coordination while activating the alkyne via π-interaction.
Related Concept Videos
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Protein Glycosylation
Glycosylation occurs in...
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Aldehydes and Ketones with Alcohols: Hemiacetal Formation
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.


