Resin-Supported Catalysts for CuAAC Click Reactions in Aqueous or Organic Solvents
摘要:
The copper-catalyzed azide-alkyne cycloaddition click reaction is a valuable process for the synthesis of libraries of drug candidates, derivatized polymers and materials, and a wide variety of other functional molecules. In some circumstances, the removal of the copper catalyst is both necessary and inconvenient. We describe here two immobilized forms of a Cu-binding ligand that has been shown to accelerate triazole formation under many different conditions, using different resin supports that are appropriate for aqueous or organic solvents. Copper leaching from these resins was modest, allowing them to be reused in many reaction/filtration cycles without recharging with metal ion. The utility of this catalyst form was demonstrated in the convenient synthesis of 20 N-acetylgalactosamine derivatives for biological testing.
Relative Performance of Alkynes in Copper-Catalyzed Azide–Alkyne Cycloaddition
摘要:
Copper-catalyzed azide-alkyne cycloaddition (CuAAC) has found numerous applications in a variety of fields. We report here only modest differences in the reactivity of various classes of terminal alkynes under typical bioconjugative and preparative organic conditions. Propargyl compounds represent an excellent combination of azide reactivity, ease of installation, and cost. Electronically activated propiolamides are slightly more reactive, at the expense of increased propensity for Michael addition. Certain alkynes, including tertiary propargyl carbamates, are not suitable for bioconjugation due to copper-induced fragmentation. A fluorogenic probe based on such reactivity is available in one step from rhodamine 110 and can be useful for optimization of CuAAC conditions.
The invention relates to sphingoglycolipid analogues and peptide derivatives thereof, which are useful in treating or preventing diseases or such as those relating to infection, atopic disorders, autoimmune diseases or cancer.
The invention relates to amino sphingoglycolipid analogues and peptide derivatives thereof, compositions comprising these compounds and methods of treating or preventing diseases or conditions using such compounds, especially diseases or conditions relating to cancer, infection, atopic disorders, autoimmune disease or diabetes.
The systematic influence of tripodal ligands on the catechol cleaving activity of iron(III) containing model compounds for catechol 1,2-dioxygenases †
作者:Matthias Pascaly、Mark Duda、Florian Schweppe、Kristin Zurlinden、Felizitas K. Müller、Bernt Krebs
DOI:10.1039/b008511l
日期:——
A series of mononuclear iron(III) complexes as functional and structural model compounds for intradiol cleaving catechol dioxygenases were synthesized. For all model compounds the iron(III) cores are in a distorted octahedral environment derived from tripodal tetradentate N4-donor ligands and a catechol. Model complexes for enzyme–substrate adducts were characterized by spectroscopic and electrochemical
Cucurbit[7]uril-improved recognition by a fluorescent sensor for cadmium and zinc cations
作者:Qing-Xia Geng、Hang Cong、Zhu Tao、Leonard F. Lindoy、Gang Wei
DOI:10.1080/10610278.2015.1117614
日期:2016.10.2
Abstract The host–guest interaction of cucurbit[7]uril (Q[7]) with the new fluorescent sensor guest molecule (BIBPAH+), formed by alkylation of the secondary amine site in N,N-bis(2-pyridylmethyl)amine with 2-(bromomethyl)benzimidazole, was investigated by fluorescence and 1H NMR spectroscopy. The results indicate the formation of an inclusion complex in a 1:1 ratio with an association constant of
Effect of Deprotonation of a Benzimidazolyl Ligand on the Redox Potential and the Structures of Mononuclear Ruthenium(II) Complexes
作者:Hongfei Sun、Mei Wang、Kun Jin、Chengbing Ma、Rong Zhang、Licheng Sun
DOI:10.1002/ejic.200700549
日期:2007.9
A monoruthenium(II) complex of the benzimidazolyl ligand and its deprotonated counterpart were prepared and structurally characterized. The reversible protonation/deprotonation process of the ancillary ligand switches the redox potential of the ruthenium(II) core from 0.69 to 0.26 V vs. Ag/AgNO3. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
制备了苯并咪唑基配体及其去质子化对应物的单钌 (II) 配合物并对其进行了结构表征。辅助配体的可逆质子化/去质子化过程将钌 (II) 核的氧化还原电位从 0.69 V 转换为 0.26 V(相对于 Ag/AgNO3)。((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)