Serendipitous late-stage modification of dipeptide by using AIBN and thioacetic acid

Abstract

Post-assembly peptide modifications have become an integral part of medicinal chemistry nowadays. This exercise is useful in finding novel bioconjugates, therapeutic peptides and protein labelling. Therefore, in our attempts towards the modification of peptides, we have tried to insert thiophene moiety in dipropargyl dipeptide in the presence of AIBN and thioacetic acid. Surprisingly, instead of thiophene group introduction, we observe the serendipitous functionalization of amide group i.e. –NHCOCH3 is converted into –NHCHO group.