نتایج جستجو برای: cycloaddition reaction
تعداد نتایج: 415203 فیلتر نتایج به سال:
Nitrile Oxide−Dehydroalanine Cycloaddition is a bioconjugation strategy between dehydroalanine-containing proteins and nitrile oxides, remarkably, in fully aqueous-buffered systems without an additional catalyst. This novel method of chemical protein modification forms isoxazoline ring enhancing the diversity function structure. The 1,3-dipolar cycloaddition reaction adds fluorescent label to f...
Abstract We describe the use of CO 2 as a promising C1 source instead in tandem Pauson‐Khand reaction. The reaction is achieved by combining reduction to using metal organic framework (MOF) catalyst with homogeneous rhodium catalysts for cycloaddition step. A range substrates were converted moderate good yields.
Montmorillonite KSF has been used as an effective and non-toxic heterogeneous catalyst for one-pot synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition of sodium azide with a wide variety of nitriles. The reaction afforded high yields of the desired products in a short reaction time under mild reaction conditions. The catalyst can be recovered by simple filtration and reuse...
Studying and controlling reactions at surfaces is of great fundamental and applied interest in, among others, biology, electronics and catalysis. Because reaction kinetics is different at surfaces compared with solution, frequently, solution-characterization techniques cannot be used. Here we report solution gradients, prepared by electrochemical means, for controlling and monitoring reactivity...
Chiral pyrrolidines and pyrrolizidines with spirooxindole ring systems are the central skeletons for numerous alkaloids and pharmacologically important compounds. Gelesmine, pseudotabersonine, formosanine, isoformosanine, morroniside and mitraphylline are some of the alkaloids containing spirooxindole ring systems. Derivatives of spirooxindole find very wide biological applications as anti micr...
The reaction of acetylides with sulfonyl azides was found to selectively form 1,5-substituted sulfonyl triazoles. This reaction thus provides access to the regioisomeric product as compared to the popular copper-catalyzed azide-alkyne cycloaddition. The reaction is efficient and selective with a variety of alkyne sources and sulfonyl azides and can incorporate an additional electrophile to yiel...
Abstract An efficient cycloaddition reaction of trifluoroacetohydrazonoyl bromides with nitroolefins was developed, which regioselectively produced 3‐trifluoromethyl‐4‐substituted pyrazoles. The has the advantages mild conditions, good tolerance functional groups and simple operation.
A new synthetic approach for the production of carbon nanomaterials (CNM) decorated with organophosphorus moieties is presented. Three different triphenylphosphine oxide (TPPO) derivatives were used to decorate oxidized multiwalled carbon nanotubes (ox-MWCNTs) and graphene platelets (GPs). The TPPOs chosen bear functional groups able to react with the CNMs by Tour reaction (an amino group), nit...
The Pauson–Khand-type reaction is formally a [2+2+1] cycloaddition involving an alkyne, an alkene and carbon monoxide catalyzed or mediated by transition metal complexes. This review focuses on the catalytic reaction and describes the recent research on the Pauson–Khand-type reaction.
An organocatalytic azide-aldehyde [3+2] cycloaddition (organo-click) reaction of a variety of enolizable aldehydes is reported. The organo-click reaction is characterized by a high rate and regioselectivity, mild reaction conditions, easily available substrates with simple operation, and excellent yields with a broad spectrum of substrates. It constitutes an alternative to the previously known ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید