Synthesis and characterization of novel chiral calix[4]arene bearing (R)-(+)-1-phenylethylamine bonded silica particles

Two novel chiral di- and tri-amide derivatives of p-tert-butylcalix4]arene were synthesized by (R)-(+)-1-Phenylethylamine via convenient reactions and then immobilized on aminopropyl functionalized silica particles. The prepared chiral calix4]arenes and their silica polymers (Calix-SP1 and Calix-SP2) were characterized using ¹H NMR, ¹³C NMR, FT-IR, and thermal and elemental analysis techniques.