Synthesis, functionalization, and isolation of planar-chiral pillar[5]arenes with bulky substituents using a chiral derivatization agent

Bulky perneopentyloxy-pillar[5]arene ( Pillar-1 ) was synthesized and its conformational mobility was investigated using variable-temperature 1 H NMR spectroscopy. The host-guest interactions between Pillar-1 and n -octyltrimethylammonium hexafluorophosphate ( OMA ) were investigated, and the formation of a 1 : 1 complex was revealed via 1 H NMR. Planar-chiral isomers were synthesized via the reaction of a hydroxy-functionalized pillar[5]arene with chiral derivatization agent ( S )-(+)-MTPA-Cl. The (Sp, R )-and (Rp, R )-forms of the pillar[5]arene diastereomers were isolated by HPLC, and their structures were analyzed by 19 F NMR. HPLC measurements indicated that racemization did not take place at 40 °C for 72 h. Bulky perneopentyloxy-pillar[5]arene was synthesized. Complexation behavior and conformational mobility were investigated using 1 H NMR spectroscopy. Isolation of planar-chiral pillar[5]arenes using a chiral derivatization agent were carried out.