A New Robust and Versatile Tetradentate Linker for Amides To be Cleaved under Mild Conditions by Unusual Complexation of the Amide Nitrogen to Cu++

摘要

The concept of weakening amide bonds by the rather unusual forced complexation of nitrogen to Cu++ is not limited to tridentate ligands and was extended in this work to tetradentate ligands as well. The use of cyclic tetradentate ligands was to no avail, but an open-chain and more-flexible tetradentate ligand allowed mild cleavage by methanolysis after complexation. The principle was applied to the development of a new linker for solid-phase chemistry, which was proven to be extremely robust, yet allowed mild cleavage after activation by Cu++ complexation. Its stability and versatility was demonstrated by the successful application to a whole plethora of different types of reactions.