In summary, the mechanism of self-promoted Nglycosylations has been thoroughly investigated. Both IR and NMR experiments have been performed, and the importance of the conformation of the TCA donors has been investigated through computational studies. Furthermore, a possible mechanistic pathway for the reaction of a sulfonyl carbamate acceptor with an α-TCA donor has been located on the potential energy surface using DFT calculations. Experiments with a competing nucleophile were carried out, which helped substantiate the mechanism, but also revealed that the N -sulfonyl carbamate acceptors have some catalytic properties. In the proposed mechanistic scenario, a favorable trajectory for attack after protonation of the α-TCA compared to a less favorable trajectory for attack of the protonated β-TCA explains the loss of stereoselectivity and increased amount of side products for glycosylation with the β-TCA compared to glycosylation with the α-TCA. Altogether, these findings provide valuable insight into both the mechanism, the scope, and the limitations of self-promoted N -glycosylations. Additionally, the study provides insight into the mechanism of glycosylation in general, and some hints of how to design stereospecific catalysts have been revealed.