C4-symmetric alkoxyresorcin[4]arene triflates: The use of palladium-catalyzed reactions in the synthesis of axially chiral derivatives with amino- and/or alkoxy-substituents

摘要

The conversion of axially chiral tetraalkoxyresorcin[4]arenes (cyclochiral resorcinarenes into the related tetrakis(triflates in high yields is described; this provides an efficient source of chiral materials for use in palladium-catalyzed transformations, including the reductive removal of triflate groups and the synthesis of compounds that are formally derived from 3-aminophenol, providing axially chiral derivatives that are nitrogen-substituted on the upper rim. Axially chiral tetrakis(triflates of tetraalkoxyresorcin[4]arenes have been obtained in high yields from the parent tetraalkoxyresorcin[4]arenes. Pd-catalysed reductive removal of the triflate groups produces axially chiral calix[4]arenes that are formally derived from 3-aminophenol. The route provides an efficient source of axially chiral calixarenes that are nitrogen-substituted on the upper rim.