Complete Bromination of Calix[4]arene by Improved Direct Synthesis

IntroductionCalixn]arenes are cavity- containing macrocycliccompounds and the cavity can be modified byintroducing substitutents R1and R2 at the lowerrim and the aromatic para- positions at the upperrim (Fig.1 ) . Since the pioneering work of Gutscheon calixn]arenes1,2 ] ,which was mainly devotedto synthesis of structures,calix n]arenes havebeen attracting attention because of their potentialfor forming inclusion complexes with cations orneutral molecules and acting as enzyme mimics3,4 ]…

Complete Bromination of Calix[4]arene by Improved Direct Synthesis

Since the pioneering work of Gutsche on calixarenes, many functionalized calixarenes have been prepared. The full bromination of calixarene by a direct process has been regarded as unavailable. Therefore, a more circuitous route including three steps has been developed. But in the present work p-tetrabromocalixarene, which serves as a potential intermediate to derive functionalized calixarenes, is successfully synthesized with a high yield by an improved direct bromination procedure. The analytical results are in complete accordance with those reported in previous literature. The reason why the conventional methods cannot provide full bromination is discussed.