Synthesis and Complexation Studies of Optically Active Aza- and Diazacrown Ethers Containing a Pyrene Fluorophore Unit

Dávid Pál,Ildikó Móczár,Martin Gede,Péter Bagi,Péter Baranyai,Péter Huszthy

doi:10.3311/ppch.14467

Abstract

Novel enantiopure azacrown [(R,R)-1 and (S,S)-1] and diazacrown [(R,R)-2–(R,R)-4 and (S,S)-2–(S,S)-4] ethers containing a pyrene fluorophore unit and two phenyl groups at their chiral centers were obtained in multistep syntheses. The action of these chemosensors is based on the photoinduced electron transfer (PET) process, thus they show fluorescence enhancement in the presence of protonated primary amines and amino acid esters. Their recognition abilities toward the enantiomers of 1-phenylethylamine hydrogen perchlorate (PEA), 1-(1-naphthyl) ethylamine hydrogen perchlorate (NEA), phenylglycine methyl ester hydrogen perchlorate (PGME), and phenylalanine methyl ester hydrogen perchlorate (PAME) were examined in acetonitrile using fluorescence spectroscopy.

Highlights

Host–guest molecular recognition of organic ammonium ions is important in a variety of processes such as the interaction of molecules bearing ammonium ions with protein receptors [1]
Other optically active crown ethers containing different fluorophore units have been synthesized to this purpose, and their enantiomeric discrimination abilities toward the enantiomers of primary amines, amino acids, amino alcohols, and their derivatives were investigated [21, 22]
The complex formation of the eight chiral ligands with the enantiomers of PEA, NEA, PGME, and PAME was studied by fluorescence spectroscopy using acetonitrile as a solvent

Summary

Introduction

Host–guest molecular recognition of organic ammonium ions is important in a variety of processes such as the interaction of molecules bearing ammonium ions with protein receptors [1]. 4.5.2 Procedure for the synthesis of sensor molecule (S,S)-4 starting from diphenol 10 and ditosylate (S,S)-23 To a suspension of diphenol derivative 10 (24 mg, 0.11 mmol) and finely powdered anhydrous K2CO3 (115 mg, 0.83 mmol) in dry MeCN (2 mL) was added a solution of ditosylate (S,S)-23 (90 mg, 0.10 mmol) in dry MeCN (4 mL) under Ar. The resulting mixture was stirred vigorously at 50 °C, and after the reaction was complete, it was allowed to cool to rt.

Results

Conclusion