Amino Surface‐Functionalized Tris(calix[4]arene) Dendrons with Rigid C 3 ‐Symmetric Propeller Cores

Dendrons composed of three functionalized cone calix[4]arene substructures covalently bound to rigid C 3 ‐symmetric tris‐anilino cores through amide linkages have been obtained by a divergent synthetic protocol involving the coupling of p ‐nitrocalix[4]arene butanoic acid 9 with tris(4‐aminophenyl)amine ( TAPA ), 1,3,5‐tris(4‐aminophenyl)benzene ( TAPB ), and 2,4,6‐tris(4‐aminophenyl)‐ s ‐triazine ( TAPT ). Two different amidation procedures were used to generate the dodecanitro intermediates (through activation of acid 9 with PyBOP catalyst or transformation into its acid chloride). The final reduction to the title dodecaamino dendrons was smoothly carried out with H 2 and Raney‐Ni catalyst.