Enhanced Selectivity of Chalcogen Bonding over Halogen Bonding Catalyzed C-glycosylation Through Differentiated Intermediate Activation.

ABSTRACT: σ-hole-based noncovalent interactions are gaining intense attention as robust tools in stereoselective carbohydrate synthesis. However, the mechanistic understanding behind the differing performance between chalcogen bonding (ChB) catalysis versus halogen bonding (XB) catalysis in chemical glycosylations still remains unresolved. Herein, we disclose a remarkable instance whereby phosphonochalcogenide (PCH) catalysis displays pronounced selectivity and reactivity elevation in aryl-C-glycosylations compared to XB catalysis. Mechanistic studies revealed that the enhanced stereocontrol can be attributed to the differentiated downstream activation of a key bicyclic intermediate. Hammett analysis supported that ChB catalysis shifted the C-glycosylation toward the S_N1 domain, while the

SUBMITTER: Guo H 

PROVIDER: S-EPMC12790375 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature