Glycosylmanganese pentacarbonyl complexes: an organomanganese-based approach to the synthesis of C-glycosyl derivatives

Preparation, structure and reactions of glycosylmanganese pentacarbonyl complexes are discussed. Anomerically pure complexes of pyranosyl and furanosyl complexes were prepared in excellent yield. The conformations of the anomeric glucosyl and mannosyl complexes were derived from detailed analysis of their 1D and 2D 1H- and 13C-NMR spectra including NOE data. The complexes are further characterized by 55Mn-NMR chemical shifts and 55Mn, 13C one-bond coupling constants. These compounds undergo various migratory insertion reactions resulting in formation of C-glycosyl derivatives. Applications of this technology to the synthesis of C-glycosyl and C-aryl glycosidic systems are discussed.