This paper is dedicated to the memory of our collaborator and friend Dr. Norbert Itzhak
Abstract
Ketocalix[n]arenes can be prepared via oxidation of the methylene groups of protected calix[n]arenes. The presence of carbonyl groups at the bridges alters the preferred conformation and reactivity of the macrocycle and provides an entry point (via nucleophilic additions reactions) to a wide array of methylene-substituted derivatives as well as calix[n]radialenes.
1 Introduction
2 Synthesis of Ketocalix[n]arenes
2.1 Ketocalix[4]arene Derivatives
2.2 Systems Possessing both Carbonyl and Bromomethane Bridges
2.3 Pentaoxoketocalix[5]arene and Hexaoxoketocalix[6]arene Derivatives
2.4 Monooxo- and Dioxoketocalix[6]arenes
3 Conformation of Ketocalixarenes
4 Reactions of Ketocalixarenes
4.1 Alkylation of the OH Groups
4.2 Intramolecular Aromatic Nucleophilic Substitution
4.3 Reduction of the Carbonyl Groups
4.4 Reaction of 5c with PhLi
4.5 Reaction with tert-Butyllithium
5 From Ketocalix[n]arenes to Calix[n]radialenes and Calix[n]rotanes
6 Summary and Outlook
Key words
macrocycles - calixarenes - cyclophanes - nucleophilic substitution - stereochemistry
