1314659-41-0Relevant articles and documents
Unusual orthogonality in the cleavage process of closely related chelating protecting groups for carboxylic acids by using different metal ions
Mundinger, Stephan,Jakob, Uwe,Bannwarth, Willi
, p. 1258 - 1262 (2014)
Three structurally related relay protecting groups for carboxylic acids that are based on chelating amines have been developed. These protecting groups can easily be introduced by coupling the carboxylic acid and the corresponding amine in the presence of 2-(1Hbenzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU). In addition to being stable to a whole array of reaction conditions, these protecting groups are also stable under acidic and basic conditions, allowing them to be used in combination with the ester protection of carboxylic acids. The cleavage of these protecting groups is activated by the chelation of metal ions, involving an unusual coordination of the amide nitrogen. Despite their similarity, cleavage of these protecting groups is possible in both a stepwise and an orthogonal fashion by applying different metal salts.
Chelating carboxylic acid amides as robust relay protecting groups of carboxylic acids and their cleavage under mild conditions
Broehmer, Manuel C.,Mundinger, Stephan,Braese, Stefan,Bannwarth, Willi
supporting information; experimental part, p. 6175 - 6177 (2011/08/03)
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. Copyright
