A solid-phase approach for the synthesis of α-aminoboronic acid peptides.

A solid-phase synthesis of α-aminoboronic acid peptides using a 1-glycerol polystyrene resin is described. Standard Fmoc solid-phase peptide chemistry is carried out to construct bortezomib and ixazomib. This approach eliminates the need for liquid-liquid extractions, silica gel column chromatography, and HPLC purifications, as products are isolated in high purity after direct cleavage from the resin.