Intramolecular direct arylation in an A,C-functionalized calix[4]arene.
A recently developed efficient method for intramolecular direct arylation is employed on a doubly functionalized calix[4]arene fixed in the cone conformation. The reaction takes place in high yield leading to meta substituted calix[4]arenes. The functionalities are located at two opposite aromatic rings and the two possible diastereomers are obtained in a 1:1 ratio. Full sets of data including crystal structures for both isomers are presented. The NMR data reveal that even at temperatures up to 120 degrees C both isomers are fixed in a flattened cone conformation with the substituted aromatic units pointing outwards.
Barton
Olaf G
OG
Organische Chemie I, Universität Bielefeld, Universitätsstr. 25, 33501 Bielefeld, Germany. oc1jm@uni-bielefeld.de
Neumann
B
B
Stammler
H-G
HG
Mattay
Jochen
J