Chelating Carboxylic Acid Amides as Robust Relay Protecting Groups of Carboxylic Acids and their Cleavage under Mild Conditions

Free choice: Carboxamides of bispicolylamine are alternative protecting groups for carboxylic acids (see scheme). As a consequence of their straightforward applicability, their high chemical stability towards a broad range of conditions, and their selective cleavage under mild conditions to give either carboxylic acids or their methyl esters, this new protection method should find widespread application in the realm of organic synthesis.