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.
Scalable Synthesis of Piperazines Enabled by Visible-Light Irradiation and Aluminum Organometallics
作者:Samuel Suárez-Pantiga、Kilian Colas、Magnus J. Johansson、Abraham Mendoza
DOI:10.1002/anie.201505608
日期:2015.11.16
The development of more active CH oxidation catalysts has inspired a rapid, scalable, and stereoselective assembly of multifunctional piperazines through a [3+3] coupling of azomethine ylides. A combination of visible‐light irradiation and aluminum organometallics is essential to promote this transformation, which introduces visible‐lightphotochemistry of main‐group organometallics and sets the basis