A New Highly Versatile Handle for Chemistry on a Solid Support: The Pipecolic Linker

Copper(II)-mediated O-arylation of protected serines and threonines

An effective protocol toward the O-arylation of β-hydroxy-α-amino acid substrates serine and threonine has been developed via Chan-Lam cross-coupling. This Cu(II)-catalyzed transformation involves benign open-flask conditions that are well-tolerated with a variety of protected (Boc-, Cbz-, Tr-, and Fmoc-) serine and threonine derivatives and various potassium organotrifluoroborates and boronic acids.

Solid-phase peptide synthesis (SPPS), C-terminal vs. side-chain anchoring: a reality or a myth

Here we review the strategies for the solid-phase synthesis of peptides starting from the side chain of the C-terminal amino acid. Furthermore, we provide experimental data to support that C-terminal and side-chain syntheses give similar results in terms of purity. However, the stability of the two bonds that anchor the peptide to the polymer may determine the overall yield and this should be considered for the large-scale production of peptides. In addition, resins/linkers which do not subject to side reactions can be preferred for some peptides.