Click Chemistry
CLICK CHEMISTRY is a new chemical research laboratory at the University of Michigan in Ann Arbor. Its goal is to provide students with a hands-on, experiential learning experience in chemistry. This includes topics such as Polymer synthesis and modification, Copper-catalyzed cycloaddition reactions, Bioconjugation reactions, Drug discovery, and more.
Bioconjugation reactions
Among the numerous advantages of click chemistry, one of its most important features is the ability to produce a variety of bioconjugation reactions. These reactions are highly thermodynamically driven, giving very high yields and minimal byproducts.
These reactions are especially well-suited for regiospecific isolation of molecules in complex biological environments. However, the byproducts must be non-toxic and physiologically stable in in vivo systems. Therefore, a variety of factors must be considered.
The most common type of bioconjugation is to tether an imaging agent or fluorescent dye to a target. Other types of bioconjugation involve conjugation of a polysaccharide to a substance. These conjugations have been accomplished with various substances, including proteins and oligonucleotides. These conjugations have also been applied to the synthesis of a novel polymeric delivery system and to the modification of surfaces of nanoparticular delivery systems.
Polymer synthesis and modification
Initially, click chemistry was conceived as a drug discovery tool. It was proposed to solve some of the problems that pharmaceutical scientists face when synthesising new molecules. Traditional chemical reactions require high temperatures and toxic catalysts. They also are difficult to carry out in vivo.
Today, the application of click chemistry in biomedical research has become a growing field of interest. This new tool may change the paradigm of polymer synthesis and therapeutics development.
Click chemistry is a group of reactions that combine to form stable linkages in biological environments. They include cycloadditions, hetero-Diels-Alder cycloadditions, and nucleophilic ring-openings. In addition to being selective, these reactions produce high yields and are easy to purify. They are also compatible with aqueous conditions. Consequently, click chemistry is highly applicable to diverse polymeric materials.
Drug discovery
Initially developed as a drug discovery tool, click chemistry has found applications in a number of different fields. Today, the synthesis of polymer networks is among the most successful applications of click chemistry. These polymer networks are often used in drug delivery.
Click chemistry was first introduced by Dr. Barry Sharpless' group in 1999. They suggested that a new tactic should be adopted for linking building blocks to create large combinatorial libraries. Rather than relying on long, tedious analog syntheses, they would use click reactions to form stable linkages. This would drastically reduce the time and cost involved in purification and allow for the generation of stereospecific byproducts.
One of the most important transformations in click chemistry is sulfur (VI) fluoride exchange. This is a chemical reaction that occurs when a strained heterocyclic electrophile opens. This is a process that helps to explain the structure-activity relationship of many SO2F compounds.
Cyclooctynes
During the last two decades, click chemistry has been gaining tremendous attention. It has become a useful technique for the selective synthesis of functional materials and biomolecule conjugates. In addition to providing a desired product in a short time, click chemistry offers outstanding functional group tolerance.
Click chemistry refers to a collection of organic reactions that link molecular components. The reaction offers high yield and selectivity, and can proceed in aqueous media without reducing its selectivity. There are numerous types of click chemistry. These include strain-promoted azide-alkyne cycloaddition, sulfur fluoride exchange, and inverse electron demand Diels-Alder. These types of chemical reactions have been used to label radioisotopes and for cancer therapy.
Click chemistry has been applied to live zebrafish. In vivo imaging of biomolecules has been made possible with this chemistry. In addition, this type of chemistry has been applied to biomimetic hydrogels.
Copper-catalyzed cycloaddition reactions
Despite the numerous applications of copper-catalyzed cycloaddition reactions, the mechanistic understanding has been incomplete. A variety of reactivity studies have postulated the mechanism of the reaction. However, the chemistry-based approach has lagged behind.
In this study, the reaction was investigated for the azido and alkyne groups. The reactivity of copper(I) complexes and monomeric copper acetylide complexes towards organic azides was determined. The Cu(I)-catalyzed azide-alkyne cycloaddition reaction was found to be very efficient for the synthesis of cyclen-tris-primary amide chelates. It was also demonstrated that the Cu(I)-catalyzed cycloaddition reaction is a powerful tool for probeging copper-catalyzed transformations.
The kinetics of the reaction were examined in a solvent-based system, which showed zeroth order kinetics. The catalytic reaction was found to be very efficient, and the kinetics were influenced by chain mobility. The rate of the overall reaction was highly dependent on the initial concentration of copper(ii).
