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1,3‐Dipolar Cycloaddition between Dehydroalanines and C,N‐Cyclic Azomethine Imines: Application to Late‐Stage Peptide Modification
Author(s) -
Bao Guangjun,
Wang Peng,
Li Guofeng,
Yu Changjun,
Li Yiping,
Liu Yuyang,
He Zeyuan,
Zhao Tiantian,
Rao Jing,
Xie Junqiu,
Hong Liang,
Sun Wangsheng,
Wang Rui
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202012523
Subject(s) - cycloaddition , chemistry , azomethine ylide , regioselectivity , peptide , combinatorial chemistry , 1,3 dipolar cycloaddition , catalysis , medicinal chemistry , organic chemistry , biochemistry
A non‐catalytic, mild, and easy‐to‐handle protecting group switched 1,3‐dipolar cycloaddition (1,3‐DC) between bi‐ or mono‐N‐protected Dha and C,N‐cyclic azomethine imines, which afford various quaternary amino acids with diverse scaffolds, is disclosed. Specifically, normal‐electron‐demand 1,3‐DC reaction occurs between bi‐N‐protected Dha and C,N‐cyclic azomethine imines, while inverse‐electron‐demand 1,3‐DC reaction occurs between mono‐N‐protected Dha and C,N‐cyclic azomethine imines. Above all, the reactions can be carried out between peptides with Dha residues at the position of interest and C,N‐cyclic azomethine imines, both in homogeneous phase and on resins in SPPS. It provides a new toolkit for late‐stage peptide modification, labeling, and peptide–drug conjugation. To shed light on the high regioselectivity of the reaction, DFT calculations were carried out, which were qualitatively consistent with the experimental observations.