Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 0947-6539
    Keywords: carbohydrates ; cluster glucosides ; convergent syntheses ; dendrimers ; neoglycoconjugates ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of carbohydratecontaining dendrimers has been achieved by a convergent growth approach. The synthetic strategy involves: 1) the synthesis of the triglucosylated derivative of tris(hydroxymethyl)methylamine (TRIS), 2) the introduction of a glycine-derived spacer and 3,3′-iminodipropionic acid derived branching units on to the TRIS derivative by amide bond formation, 3) condensation of the above saccharidecontaining dendrons with a trifunctional 1,3,5-benzenetricarbonyl derivative, used as the core, by formation of amide bonds, and 4) deprotection of the saccharide units. A 9-mer and an 18-mer, carrying nine and eighteen saccharide units at the periphery, respectively, have been synthesized, in high yields at each step, by this synthetic strategy. By a variety of chromatographic and spectroscopic techniques, the dendrimers were shown to be structurally homogeneous, monodisperse, and error-free at all steps in their growth. These investigations were complemented by molecular modeling studies on the dendrimers. The presence of slightly distorted C3 symmetry was noted in both the 9-mer and the 18-mer.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0947-6539
    Keywords: catenanes ; chirality ; enantioselection ; receptors ; self-assembly ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The design of a new class of chiral [2]catenanes is reported. The self-assembly of [2]catenanes comprising one or two 3,3′-bitolyl spacers in the π-electron-deficient component, and bis-p-phenylene-34-crown-10 (BPP 34 C 10) as the π-electron-rich component, is described. The X-ray crystal structures, together with solution-state dynamic 1H NMR spectroscopic studies, show that the degree of order characterizing the molecular structures is substantially different from that of the “parent” [2]-catenane, comprising cyclobis(paraquat-p-phenylene) and BPP34C 10. When appropriately substituted in their ortho positions, bitolyl compounds can support axial chirality: the self-assembly of axially chiral [2]catenanes, comprising one or two 3,3′-disubstituted-2,2′-dihydroxy-1,1′-binaphthyl spacers, has been achieved in good yields, showing that the introduction of the bulky, axially chiral spacer and the consequent distortion of the cavity of the π-electron-deficient component still permits good molecular recognition between the components leading to efficient catenane production. X-ray crystallography suggests that this recognition is driven by hydrogen bonding and π-π stacking interactions between the complementary subunits. The hydroxyl groups on the chiral spacer were further functionalized as benzoyl esters in a [2]catenane as well as in the tetracationic cyclophanes; that is, chemistry can be done on these catenanes. The chiral tetracationic cyclophanes exhibit good enantiomeric differentiation toward the D- and L-enantiomers of aromatic amino acids in water and their N-acetylated derivatives in organic solvents.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...