Related Experiment Video
Updated: Mar 25, 2026

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Bis-tert-Alcohol-Functionalized Crown-6-Calix[4]arene: An Organic Promoter for Nucleophilic Fluorination
Vinod H Jadhav1, Wonsil Choi1, Sung-Sik Lee2
1Department of Chemistry, Inha University, 100 Inha-ro, Nam-gu, Incheon, 402-751, Korea), Fax: (+82) 32-867-5604.
Abstract:
A bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA) was designed and prepared as a multifunctional organic promoter for nucleophilic fluorinations with CsF. By formation of a CsF/BACCA complex, BACCA could release a significantly active and selective fluoride source for SN2 fluorination reactions. The origin of the promoting effects of BACCA was studied by quantum chemical methods. The role of BACCA was revealed to be separation of the metal fluoride to a large distance (>8 Å), thereby producing an essentially "free" F(-). The synergistic actions of the crown-6-calix[4]arene subunit (whose O atoms coordinate the counter-cation Cs(+)) and the terminal tert-alcohol OH groups (forming controlled hydrogen bonds with F(-)) of BACCA led to tremendous efficiency in SN2 fluorination of base-sensitive substrates.
More Related Videos
10:10Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes
Published on: July 28, 2018
08:43Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives
Published on: January 19, 2016
Related Concept Videos
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Hydroboration-Oxidation of Alkenes
Nucleophilic Aromatic Substitution: Elimination–Addition
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Reactions at the Benzylic Position: Halogenation