First Synthesis of Upper Rim Mono and Dinitrone Calix[4]arene Derivatives

Abstract

A new class of calix[4]arene derivatives bearing one or two nitrone groups on the upper rim has been synthesized using the oxidation of chiral imines with hydrogen peroxide. The imine intermediates were obtained via amination of the diformyl derivative. The 1 H NMR spectra and X-ray data indicated a 1,3-disubstituted cone conformation for the imine derivatives and the existence of a single (E,E) isomer. The structural identity of the nitrone derivatives was confirmed from NMR, IR and ES-MS data. Both mono and dinitrone calix[4]arenes were in E configuration.

Calix[4]arene‐tetranitrone as crosslinker in dental composite materials

“…Surprisingly, up to now, there have been only two publications dealing with the synthesis and applications of calixarenes bearing 1,3‐dipolar nitrones 17, 18. Thus, in the present paper, we present our results dealing with the synthesis and modification via cyclo‐addition of new calix[4]arene derivatives bearing four nitrone functions in the ‘upper rim’.…”

Preconcentration and Determination of Trace Silver Ion Using Benzothiazole Calix[4]arene Modified Silica by Flow Injection Flame Atomic Absorption Spectrometry

“…21,22 In a 100 mL two-necked round-bottomed flask, benzothiazole calix [4]arene or L1 (0.50 g, 0.70 mmol) and chloroform (20 mL) were magnetically stirred at -10 C under nitrogen atmosphere for 30 min. Then, 1,1-dichlorodimethyl ether (1.50 mL, 15.40 mmol) and 0.1 M tin(IV) chloride (7.70 mL, 7.70 mmol) were added and the mixture was stirred at room temperature for 1 h. Dichloromethane (200 mL) was added and the mixture was acidified with 3 M HCl (100 mL).…”