Synthesis of C3v-Symmetrical 1,3,5-Tris-Protected Calix[6]arene-Based Molecular Platforms.

Few synthetic methodologies that yield tris-functionalized C3v-symmetrical calix[6]arenes have been reported. In this work, three allyl protecting groups are selectively placed in 1,3,5 alternate positions of three pristine calix[6]arenes, each differing by their substituent on the large rim, resulting in three new C3v-symmetrical molecular platforms. Removal of the protecting allylic groups gives access to sophisticated calix[6]arenes that can be further modified. The potential of these new C3v-symmetrical molecular platforms is notably exemplified through the development of a new family of calix[6]arene-based N ligands.