Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Singly bridged calix

Geraci1, Piattelli, Chessari

  • 1Dipartimento di Chimica, Universita di Salerno, Baronissi (SA), Italy.

The Journal of Organic Chemistry
|September 19, 2000
PubMed
Summary

Directly alkylating calixarenes with poly(ethylene glycol) ditosylates using different bases yields various crowned calixarene isomers. Base selection controls regioselectivity, influencing the crown ether chain

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Use of Filgrastim for Ticlopidine Induced Neutropenia Following Coronary Stenting.

The Journal of invasive cardiology·2000
Same author

Experimental evidence from an animal model of adenocarcinoma that chronic inflammation enhances lung cancer risk

Chest·2000
Same author

Affinity reagents against tumour-associated extracellular molecules and newforming vessels.

Advanced drug delivery reviews·2000
Same author

Gas-rich galaxy pair unveiled in the lensed quasar 0957+561

Science (New York, N.Y.)·2000
Same author

Fluoride binding in hemoproteins: the importance of the distal cavity structure

Biochemistry·1998
Same author

Swift-Hohenberg equation for optical parametric oscillators.

Physical review. A, Atomic, molecular, and optical physics·1996

Area of Science:

  • Supramolecular Chemistry
  • Organic Synthesis
  • Macrocyclic Chemistry

Background:

  • Calixarenes are versatile macrocyclic hosts with tunable cavities.
  • Crowned calixarenes integrate crown ether units onto calixarene scaffolds, offering unique host-guest properties.
  • Controlling the regioselectivity of crown ether incorporation is crucial for designing functional supramolecular systems.

Purpose of the Study:

  • To investigate the direct synthesis of crowned calix[8]arenes via alkylation.
  • To explore the influence of different bases and poly(ethylene glycol) chain lengths on regioselectivity.
  • To characterize the resulting crowned calix[8]arene derivatives and understand their conformational behavior.

Main Methods:

  • Direct alkylation of p-tert-butylcalix[8]arene with poly(ethylene glycol) ditosylates.
  • Utilizing various bases (K2CO3, Cs2CO3, NaH) to control reaction regioselectivity.
  • Characterization using dynamic Nuclear Magnetic Resonance (NMR) spectroscopy and molecular modeling studies.

Main Results:

  • Selective formation of 1,3-calix[8]crowns with K2CO3.
  • Preferential synthesis of 1,5-isomers using Cs2CO3, especially with shorter PEG chains (e.g., 1,5-crown-2, 88%; 1,5-crown-3, 78%).
  • NaH promotes the formation of 1,4-isomers (up to 46% yield), sometimes exclusively, alongside 1,2-isomers.
  • Conformational analysis reveals that the polyether chain can restrict molecular flexibility.

Conclusions:

  • The choice of base is critical for directing the regioselective synthesis of crowned calix[8]arenes.
  • Crown ether chain length and bridging mode influence the conformational properties of the synthesized macrocycles.
  • This study provides a facile route to diverse crowned calix[8]arene architectures with potential applications in molecular recognition and sensing.

Related Experiment Videos