Stereoselective Aromatic O -Glycosylation of Glycosyl Chloride with Arylboronic Acid under an Air Atmosphere.

A novel exclusive β-selective O -aryl glycosylation was developed using glycosyl chloride and arylboronic acid with a palladium catalyst under an air atmosphere. The reaction was insensitive to moisture and characterized using readily available and bench-stable glycosyl chloride and arylboronic acid as substrates. A diverse range of substrate scopes, including various arylboronic acids and glycosyl chloride donors, was well-tolerated in this method. Arylboronic acid was oxidized by O 2 in air to produce phenol as the aromatic source. This new strategy provides an alternative route and may find broad applications in efficient synthesis of bioactive O -aryl glycosides in the future.