Addressing mechanistic issues in the coupling of isonitriles and carboxylic acids: Potential routes to peptidic constructs

Mechanistic issues surrounding the two component coupling (2CC) reaction of carboxylic acids with isonitriles have been investigated. Experimental details suggest the formimidate carboxylate mixed anhydride intermediate exists in both interdictable and noninterdictable form. Furthermore, the 2CC reaction has been applied to the synthesis of a tripeptide featuring two formyl functional groups.