Thiazolidine Deprotection by 2-Aminobenzamide-Based Aldehyde Scavenger for One-Pot Multiple Peptide Ligation

Strategies for one-pot peptide ligation enable chemists to access synthetic proteins at a high yield in a short time. Herein, we report a new one-pot multi-segments ligation strategy using N-terminal thiazolidine (Thz) peptide and a formaldehyde scavenger. Among our designed 2-aminobenzamide-based aldehyde scavengers, 2-amino-5-methoxy-N’,N’-dimethylbenzohydrazide showed a good ability to capture formaldehyde from Thz at pH 4.0. This scavenger had compatibility with the conditions of native chemical ligation at pH 7.5. Using this scavenger for a model peptide ligation system, we performed one-pot four-segment ligation at a high yield without significant side reactions.