Palladium-Catalyzed Stereocontrolled Synthesis of Aryl- C -Glycosides from Arylboronic Acids and Glycal Enones Through 1,4-Conjugate Addition Reactions

1,4-Conjugate addition of arylboronic acids to the glycal enones delivered 2-deoxy-alpha-aryl-C-glycosides in good yields. The reaction was catalyzed by palladium acetate in the presence of trifluoroacetic acid and 1,10-phenanthroline. A wide range of glycal enones derived from D-glucal, D-galactal, and D-rhamnal participated in the coupling reaction with different arylboronic acids smoothly. Different protecting groups including benzyl, acetyl, pivaloyl, and benzoyl were compatible under optimized conditions.