Functionalization of GlucoPyranosides at position 5 by 1,5 C-H insertion of Rh(II)-Carbenes: Dramatic influence of the anomeric configuration.

Herein, a C-H bond functionalization approach is reported as a new route towards non-natural glycosides having a quaternary position 5. The development of this transformation furthermore reveals that insertion of Rh(II)-carbenes into the C5-H bond is controlled by remote stereoelectronic effects induced by the axial or equatorial orientation of the aglycone.