Rigid Duplex α-Cyclodextrin Reversibly Connected With Disulfide Bonds. Synthesis and Inclusion Complexes

The rigid duplex cyclodextrin 6 composed of two α-cyclodextrin macrocycles connected with two disulfide bonds in “transannular” (C6I, C6IV) positions was prepared from partially debenzylated α-cyclodextrin 1 in four steps in 73% overall yield. In the last key step involving oxidative coupling of the...

Full description

Saved in:
Bibliographic Details
Published in:Journal of organic chemistry 2009-02, Vol.74 (3), p.1082-1092
Main Authors: Kumprecht, Lukáš, Buděšínský, Miloš, Vondrášek, Jiří, Vymětal, Jiří, Černý, Jiří, Císařová, Ivana, Brynda, Jiří, Herzig, Vladimír, Koutník, Petr, Závada, Jiří, Kraus, Tomáš
Format: Article
Language:English
Subjects:
Alcohols - chemistry
alpha-Cyclodextrins - chemical synthesis
alpha-Cyclodextrins - chemistry
Carbohydrates with 4, 5, 6, ... C atoms, dissacharides and oligosaccharides
Carbohydrates. Nucleosides and nucleotides
Chemistry
Crystallography, X-Ray
Dimerization
Disulfides - chemistry
Exact sciences and technology
Models, Molecular
Molecular Conformation
Organic chemistry
Preparations and properties
Thermodynamics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The rigid duplex cyclodextrin 6 composed of two α-cyclodextrin macrocycles connected with two disulfide bonds in “transannular” (C6I, C6IV) positions was prepared from partially debenzylated α-cyclodextrin 1 in four steps in 73% overall yield. In the last key step involving oxidative coupling of the thiol 5, predominance of the target duplex 6 can be attained under conditions of thermodynamic control. The structure of duplex cyclodextrin was established by MS as well as 2-D NMR methods and confirmed by a single-crystal X-ray analysis. The ability of the duplex cyclodextrin 6 to bind α,ω-alkanediols (C9−C14) and 1-alkanols (C9 and C10) was studied by isothermal titration calorimetry in aqueous solutions. The stability constants of the complexes gradually increase with the alkyl chain length and reach an unprecedently high value of K = 8.6 × 109 M−1 for 1,14-tetradecanediol. It was found that the doubly bridged dimer 6 exhibits higher binding affinity toward the series of α,ω-alkanediols than the singly bridged analogue 10 by about 2 orders of magnitude in K (M−1) or 3.1−3.3 kcal/mol in ΔG°, the enhancement being due to enthalpic factors. Theoretical calculations using DFT-D methods suggest that the enthalpic contribution stems from dispersion interactions.
ISSN:0022-3263
1520-6904
DOI:10.1021/jo802139s