New and Highly Efficient Immonium Type Peptide Coupling Reagents: Synthesis, Mechanism and Application

A series of novel immonium type coupling reagents BOMI, BDMP, BPMP, DOMP, SOMP, FOMP and AOMP were designed and synthesized. It was shown that most of these reagents were more efficient in peptide synthesis than conventional methods due to the advantages of high reactivity, low racemization and good yields. The reaction mechanism was proposed and studied by 1H NMR, IR, UV and HPLC.