posted on 2022-01-26, 14:06authored byQiuyuan Wang, Mengnan Lai, Huajun Luo, Keke Ren, Jingrui Wang, Nianyu Huang, Zhangshuang Deng, Kun Zou, Hui Yao
An open-air palladium-catalyzed O-glycosylation
was developed using
glycals and arylboronic acids with base additives at ambient conditions.
The novel approach enabled facile access to various O-glycosides in high yields, with exclusive 1,4-cis-stereoselectivity tolerating reactive hydroxyl/amino groups. Mechanistic
studies indicated that chemo-/stereoselectivity arose from the coordination
between palladium and phenols generated in situ by
oxidizing arylboronic acids, followed by an intramolecular attack.
Isotope-labeling experiments revealed that the oxygen of O-glycosidic
bonds came from O2.