Electrophilic aromatic substitution in the calix[n]arene series is a well-established procedure leading exclusively to para-substituted derivatives. An unprecedented regioselectivity of the mercuration reaction leading to the meta-substituted calix[4]arenes is described.
These compounds represent a new type of substitution pattern in classical calixarene chemistry and open the door for the straightforward synthesis of inherently chiral receptors based on calixarenes.