Description: Na-Ascorbate can be used as a reduction reagent for Cu(I)-catalyzed Alkyne-Azide click chemistry reactions (CuAAC). It catalyzes the reduction of Cu(II) sources such as CuSO4 thereby releasing catalytically reactive Cu(I) ions. Ideally, solutions should be freshly prepared in ddH2O shortly before use.
Table of Contents
How do you quench a click reaction?
Performing the CuAAC reaction A premixed solution of CuSO4 (2.5 ฮผL) and 1 (5.0 ฮผL). 25 ฮผL of aminoguanidine. 25 ฮผL of sodium ascorbate. Close the tube (to prevent more oxygen from diffusing in), mix by inverting the tube several times, or attach to a slow rotisserie (approx.
Which transition metal is used in carrying out click reaction?
The common process for the click reaction is the transition metal catalyzed synthesis of 1,2,3-triazoles. 1,3-dipolar cyclo-addition of an azide and an alkyne catalyzed by Cu is the most extensively used click-chemistry pathway due to its high selectivity and simplicity [31].
Why do we click in chemistry?
Click chemistry refers to a group of reactions that are fast, simple to use, easy to purify, versatile, regiospecific, and give high product yields. While there are a number of reactions that fulfill the criteria, the Huisgen 1,3-dipolar cycloaddition of azides and terminal alkynes has emerged as the frontrunner.
How fast is click reaction?
As one of the best click reactions to date, the copper-catalyzed azide-alkyne cycloaddition features an enormous rate acceleration of 107 to 108 compared to the uncatalyzed 1,3-dipolar cycloaddition.
How does click reaction work?
Click reactions occur in one pot, are not disturbed by water, generate minimal and inoffensive byproducts, and are “spring-loaded”โcharacterized by a high thermodynamic driving force that drives it quickly and irreversibly to high yield of a single reaction product, with high reaction specificity (in some cases, with …
What is the major product formed in click reaction?
Click chemistry is the 1,3-dipolar cycloaddition of an azide and alkyne to form 1,2,3-triazole, which has been applied for a wide range of applications due to its simple workup and purification steps, rapidly creating new products (Fig. 5.9) [96,97].
Are triazoles aromatic?
5.8. 1 1,2,3-Triazole. 1,2,3-Triazole is an unsaturated, aromatic, five-membered, ฯ-excessive nitrogen heterocycle with a 6ฯ electron ring system, comprised of three regular nitrogen and two carbon atoms with two double bonds.
What is Staudinger ligation?
Staudinger ligation reaction scheme (azide-phosphine conjugation). Phosphine-activated proteins or labeling reagents react with azide-labeled target molecules to form aza-ylide intermediates that quickly rearrange in aqueous conditions to form stable amide bonds between reactant molecules.
Why ascorbic acid is a reducing agent?
In fact, all known physiological and biochemical functions of ascorbate are due to its action as an electron donor. The ability to donate one or two electrons makes AscHโ an excellent reducing agent and antioxidant. Ascorbate readily undergoes pH-dependent autoxidation producing hydrogen peroxide (H2O2).
How do you make sodium ascorbate from ascorbic acid?
Sodium ascorbate is produced by dissolving ascorbic acid in water and adding an equivalent amount of sodium bicarbonate in water. After cessation of effervescence, the sodium ascorbate is precipitated by the addition of isopropanol.
Is click chemistry Green?
The click chemistry in a broad sense is about using easier reactions to make compounds for certain functions of drugs. The click chemistry used as a green synthesis, because it allows the basic principles of green chemistry given by Anastas and Warner.
What is difference between regioselective and Regiospecific?
Generally speaking, if a reaction takes place that produces two or more products and one of the products predominates, the reaction is said to be regioselective. On the other hand, if one of the products completely predominates (or nearly so), then the reaction is said to be regiospecific.
Why is Bioconjugation important?
Bioconjugation reactions play a critical role in the modification of proteins. Because of recent advances in the study of biomolecules, proteins can be modified to perform a variety of functions, including cellular tracking, imaging biomarkers, and target drug delivery.
Are there Cycloalkynes?
In organic chemistry, a cycloalkyne is the cyclic analog of an alkyne. A cycloalkyne consists of a closed ring of carbon atoms containing one or more triple bonds. Cycloalkynes have a general formula CnH2nโ4.
What is CuAAC reaction?
The CuAAC reaction was a breakthrough in triazole chemistry. The reactions of organic azides with terminal alkynes were shown to be accelerated by copper ions and to proceed regioselectively under these conditions, giving the 1,4-disubstituted 1,2,3-triazole regioisomer exclusively.
What is modular reaction?
Modular chemical reactions can be used for three different purposes in macromolecular chemistry: (i) as a polymerization step in a chain- or step-growth polymerization, (ii) as a reaction for the chain-end, side-chain or site-specific modification of preformed macromolecules and (iii) as a ligation tool for the …
What is azide ion?
Azide is the anion with the formula Nโ3. It is the conjugate base of hydrazoic acid HN 3. Nโ3 is a linear anion. Organic azides are organic compounds with the formula RN 3, containing the azide functional group. The dominant application of azides is as a propellant in air bags.
What is the mechanism of action for triazoles?
Mechanism of Action The triazoles are potent inhibitors of ergosterol synthesis, the major membrane sterol of fungi. They block the cytochrome P450-dependent enzyme C-14 alpha-demethylase, which is needed to convert lanosterol to ergosterol.
Are triazoles stable?
It is a surprisingly stable structure compared to other organic compounds with three adjacent nitrogen atoms. However, flash vacuum pyrolysis at 500 ยฐC leads to loss of molecular nitrogen (N2) leaving a three-member aziridine ring. Certain triazoles are relatively easy to cleave due to ringโchain tautomerism.
How do triazoles work?
1.7 Triazole These agents work by inhibiting the synthesis of ergosterol, a critical component of fungal cell membranes (more specifically, by inhibiting the cytochrome P450 fungal enzyme C-14ฮฑ-dimethylase).
How can we reduce azides to amines?
Organic azides are easily and chemoselectively reduced to the corresponding amines by reaction with dichloroindium hydride under very mild conditions. ฮณ-Azidonitriles give pyrrolidin-2-imines in an outstanding cyclization.
What do you mean by Ylide?
An ylide is defined as a neutral dipolar molecule containing a negatively charged atom directly attached to a positively charged heteroatom, in which the negatively charged atom is a nucleophilic center and the onium group is usually a good leaving group.
What is aza Wittig reaction?
Aza-Wittig reactions are similar to Wittig reactions in that they also involve the reaction of a phosphonium ylide, in this case an iminophosphorane (or phosphinimide) such as 39, with a carbonyl group containing compound to form the carbonโnitrogen double bond of an imine along with a byproduct phosphine oxide such as …
How does vitamin C neutralize free radicals?
As being a reducing substance and an electron donor, during free radical scavenging, vitamin C donates high-energy electrons to neutralize free radicals, and it is oxidized to dehydroascorbic acid.