From all of the above findings, we propose the mechanistic pathway in Figure for self-promoted Nglycosylations. The high stereoselectivity observed for the α-TCA is explained by the formation of an ion pair with a very favorable trajectory, where the leaving group is hydrogen bonded to O-2 (A). A similar ion pair cannot be formed by the β-TCA, where the leaving group instead will be hydrogen bonded to the endocyclic oxygen, which means that the nucleophilic glycosyl acceptor will be in an unfavorable position for attack (B). Furthermore, a cavity, which allows for attack by competing nucleophiles, is created, leading to the formation of multiple competing pathways.