Modification and Optimization of the Bis-picolylamide-Based Relay Protection for Carboxylic Acids to be Cleaved by Unusual Complexation with Cu2+ Salts
摘要:
A simple modification of our recently published protection scheme for carboxylic acids as amides resulted in a new protecting group with significantly improved properties. It requires shorter reaction times for deprotection and allows us to replace Cu(OTf)(2) by CuCl2, indicating at the same time the importance of the nature of the anion of the Cu2+ source. Since the new scheme fulfills all criteria required for an ideal protection group it should find widespread application in synthetic organic chemistry.
Modification and Optimization of the Bis-picolylamide-Based Relay Protection for Carboxylic Acids to be Cleaved by Unusual Complexation with Cu2+ Salts
摘要:
A simple modification of our recently published protection scheme for carboxylic acids as amides resulted in a new protecting group with significantly improved properties. It requires shorter reaction times for deprotection and allows us to replace Cu(OTf)(2) by CuCl2, indicating at the same time the importance of the nature of the anion of the Cu2+ source. Since the new scheme fulfills all criteria required for an ideal protection group it should find widespread application in synthetic organic chemistry.
Unusual Orthogonality in the Cleavage Process of Closely Related Chelating Protecting Groups for Carboxylic Acids by Using Different Metal Ions
作者:Stephan Mundinger、Uwe Jakob、Willi Bannwarth
DOI:10.1002/chem.201302708
日期:2014.1.27
conditions, these protectinggroups 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 protectinggroups is activated by the chelation of metal ions, involving an unusual coordination of the amide nitrogen. Despite their similarity, cleavage of these protectinggroups is possible in both a stepwise