Modular Stereoselective Synthesis of (1→2)-C-Glycosides based on the sp(2) -sp(3) Suzuki-Miyaura Reaction.

This work reports a modular and rapid approach to the stereoselective synthesis of a variety of α- and β-(1→2)-linked C-disaccharides. The key step is a Ni-catalyzed cross-coupling reaction of D-glucal pinacol boronate with alkyl halide glycoside easily prepared from commercially available D-glucal. The products of this sp(2) -sp(3) cross-coupling reaction can be converted to glucopyranosyl, mannopyranosyl, or 2-deoxy-glucopyranosyl C-mannopyranosides by one- or two-step stereoselective oxidative-reductive transformations. To the best of our knowledge, we demonstrated the first synthetic application of a challenging sp(2) -sp(3) Suzuki-Miyaura cross-coupling reaction in carbohydrate chemistry.