Synthesis of the TACO Scaffold as a New Selectively Deprotectable Conformationally Restricted Triazacyclophane Based Scaffold

The synthesis of a new triazacyclophane scaffold (TACO scaffold) containing three selectively deprotectable amines is described. The TACO scaffold is conformationally more constrained than our frequently used TAC scaffold, due to introduction of a substituent on the para position of the benzoic acid hinge, which prevents ring flipping and makes it more attractive than the TAC scaffold for preparation of artificial receptor molecules or for mimicking discontinuous epitopes toward protein mimics when more preorganization is required.