Abstract : Fonctionalisation of unactivated C-H bonds is a tremendous challenge in organic chemistry. In this work, intramolecular catalytic amination was performed on a sugar-derivative substrate. Insertions into a pseudoanomeric C–H bond in a C-glycoside carrying a 1-carbamoyloxymethyl group were independent of the configuration of this carbone whereas the corresponding 1-sulfamoyloxymethyl derivatives were strongly dependent of that configuration. The insertion products which contain a spiranic N,O-acetal function might be functionalized to afford new original glycomimetics. A model study on piperidine substrates was performed to evaluate endocyclic heteroatom effect. The regioselectivity of intramolecular amination of these compounds was found to be completely different from that usually observed. The unexpected seven-membered ring formation was then rationalized by decisive stereoelectronics and conformational factors. Finally, to exploit these results, we designed a new general synthetic strategy leading to 4-amino-imino-Cglycoside. In this process, the sulfamoyloxymethyl group was used several times as a “molecular activating arm” to functionalize all positions of a monosubstituted piperidine. The total synthesis of various iminosugars was achieved to illustrate the synthetic potential of this strategy and to open the way to the discovery of new therapeutic agents.