A macrocyclic chalcogen bonding catalysis system†

Abstract

Chalcogen bonding has emerged as a new catalysis strategy capable of solving reactivity and selectivity problems in a diverse array of chemical reactions. However, a macrocyclic chalcogen bonding catalysis system remains undeveloped in this field. Herein, we report the first example of the development of macrocyclic chalcogen bonding catalysts and proof-of-concept studies on their catalytic capability. Tellurium centers in these macrocyclic chalcogen bonding catalysts can form competitive host–guest interactions between the catalyst and glycosyl acceptors and donors, enabling the development of a dynamic glycosylation approach. In the presence of the same macrocyclic catalyst and the same reactants, the glycosylation process could be controlled to shift between S_N1 and S_N2 reaction pathways through the formation of different host–guest complexes. This dynamic glycosylation mechanism can lead to high stereoselectivity by simply increasing the concentration of glycosyl acceptors.