Domino meta-C-H Ethyl Glycosylation by Ruthenium(II/III) Catalysis: Modular Assembly of meta-C-Alkyl Glycosides

Glycosyl anomeric radical addition reactions have been well-explored and proved efficient for the C-alkyl glycosides synthesis, but multicomponent Domino transformations for the rapid and controllable construction of structurally diversified C-alkyl glycosides in a single step are still rare. In contrast, we, herein, report a ruthenium(II)-catalyzed Domino meta-C-H ethyl glycosylation, enabling the construction of challenging meta-C-alkyl glycosides. Our ruthenium(II) catalysis was reflected by the mild reaction condition, exclusive meta-site selectivity and high levels of anomeric selectivity. In addition, the ruthenium(II)-catalyzed Domino meta-C-H glycosylation allowed for the synthesis of versatile 1,2-trans-C-alkyl glycosides with commercially available vinyl arenes, acrylates and easily accessible glycosyl bromides.