The increasing demands for the synthetic peptides and proteins have greatly advanced
the method and strategy of chemical synthesis. In this Synpacts article, we will share
our new ligation concept, serine/threonine ligation (STL), and the application in
the synthesis of cyclic peptides, particularly backbone-constrained cyclic tetrapeptides.
This ligation relies on the chemoselective reaction between N-terminal serine/threonine
and a C-terminal salicylaldehyde ester.
Key words
cyclization - ring contraction - peptides - imines - chemoselectivity - ring closure
