Native chemical ligation (NCL) is an invaluable tool in the total chemical synthesis of proteins. Ligation auxiliaries overcome the requirement for cysteine. However, the reported auxiliaries remained limited to glycine-containing ligation sites and the acidic conditions applied for cleavage of the typically applied N-benzyl-type linkages promote side reactions. With the aim to improve upon both ligation and cleavage, we systematically investigated alternative ligation scaffolds that challenge the N-benzyl dogma. The study revealed that auxiliary-mediated peptide couplings are fastest when the ligation proceeds via 5-membered rather than 6-membered rings. Substituents in α-position of the amine shall be avoided. We observed, perhaps surprisingly, that additional β-substituents accelerated the ligation conferred by the β-mercaptoethyl scaffold. We also describe a potentially general means to remove ligation auxiliaries by treatment with an aqueous solution of triscarboxyethylphosphine (TCEP) and morpholine at pH 8.5. NMR analysis of a C-labeled auxiliary showed that cleavage most likely proceeds through a radical-triggered oxidative fragmentation. High ligation rates provided by β-substituted 2-mercaptoethyl scaffolds, their facile introduction as well as the mildness of the cleavage reaction are attractive features for protein synthesis beyond cysteine and glycine ligation sites.