HOBt and HOAt-derived immonium salts: new and highly efficient coupling reagents for peptide synthesis

Novel HOBt- and HOAt-derived immonium type coupling reagents BDMP, BPMP and AOMP were shown to be very efficient for peptide synthesis with high reactivity, low racemization and good yields. X-Ray analysis indicates BOMI exists as the N-substituted form rather than as the O-substituted form assigned previously. A mechanism for amide bond formation mediated by these reagents was proposed and studied.