Click chemistry is a concept introduced by K. Barry Sharpless in 2001 and describes chemistry tailored to generate substances quickly and reliably by joining small units together as nature does. Karl Barry Sharpless (born April 28, 1941) is an American chemist renowned for his work on organometallic chemistry. ... Multicolored chemicals are frequent hallmarks of chemistry. ... The deepest visible-light image of the universe, the Hubble Ultra Deep Field. ...

Explanation

In biochemistry, after all, proteins are made from repeating amino acid units and sugars are made from repeating monosaccharide units. The connecting units are based on carbon - hetero atom bonds C-X-C rather than carbon - carbon bonds. In addition, enzymes ensure that chemical processes can overcome large enthalpy hurdles by division into a series of reactions each with a small energy step. Mimicking nature in organic synthesis of new pharmaceuticals is essential given the large number of possible structures. Biochemistry is the study of the chemistry of life, a bridge between biology and chemistry that studies how complex chemical reactions give rise to life. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... Monosaccharides are the simplest form of carbohydrates. ... In organic chemistry a hetero atom refers to nitrogen, oxygen, sulfur, and the halogens. ... Ribbon diagram of the catalytically perfect enzyme TIM. An enzyme is a protein that catalyzes, or speeds up, a chemical reaction. ... Enthalpy (symbolized H, also called heat content) is the sum of the internal energy of matter and the product of its volume multiplied by the pressure. ...

In 1996 Guida calculated the size of the pool of drug candidates at 10⁶³, based on the presumption that a candidate consists of less than 30 non-hydrogen atoms, weights less than 500 daltons, is made up of atoms of hydrogen, carbon, nitrogen, oxygen, phosphorous, sulfur, chlorine and bromine, and is stable at room temperature and stable towards oxygen and water. Click chemistry in combination with combinatorial chemistry, high-throughput screening and building chemical libraries speeds up new drug discoveries by making each reaction in a multistep synthesis fast, efficient and predictable. The unified atomic mass unit (u), or dalton (Da), is a small unit of mass used to express atomic masses and molecular masses. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Phosphite is a polyatomic ion with the formula: PO33-. The archaic name for phosphite was phosphorous, not to be confused with phosphorus. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... General Name, Symbol, Number bromine, Br, 35 Chemical series halogens Group, Period, Block 17, 4, p Appearance gas/liquid: red-brown solid: metallic luster Atomic mass 79. ... Room temperature, in laboratory reports, is taken to be roughly 21–23 degrees Celsius (69-73 degrees Fahrenheit), or 294–296 kelvins. ... Combinatorial chemistry involves the rapid synthesis and/or the computer simulation of a large number of different but structurally related molecules. ... It has been suggested that Virtual_high_throughput_screening be merged into this article or section. ...

A chemical transformation that is part of click chemistry obeys the following criteria:

• application modular and wide in scope
• obtains high chemical yield
• generates inoffensive byproducts
• is stereospecific
• simple reaction conditions
• has readily available starting materials and reagents
• no solvent involved or a benign solvent (preferably water)
• easy product isolation by crystallisation or distillation but not preparative chromatography
• physiologically stable
• large thermodynamic driving force > 84 kJ/mol for a fast reaction with a single reaction product. A distinct exothermic reaction makes a reactant "spring loaded".
• high atom economy

Chemical reactions that fit the bill are: Yield in chemistry, also known as chemical yield and reaction yield, is the amount of product obtained in a chemical reaction. ... In chemistry, a stereospecific chemical reaction yields different stereoisomeric reaction products from two stereoisomeric reactants depending on the reaction conditions. ... A solvent is a liquid that dissolves a solid, liquid, or gaseous solute, resulting in a solution. ... Crystal (disambiguation) Insulin crystals A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... Strathisla whisky distillery in Keith, Scotland Distillation is a method of separation of substances based on differences in their vapour pressures. ... Chromatography is a family of analytical chemistry techniques for the separation of mixtures. ... A kilojoule (abbreviation: kJ) is a unit of energy equal to 1000 joules. ... The mole and its simple conversions into different units of measurements. ... Atom economy describes the conversion efficiency of a chemical process in terms of all atoms involved. ...

• cycloaddition reactions, particularly the Huisgen 1,3-dipolar cycloaddition as well as Diels-Alder reactions
• nucleophilic substitution especially to small strained rings like epoxy and aziridine compounds
• carbonyl-chemistry-like formation of ureas and amides but not reactions of the aldol type due to low thermodynamic driving force.
• addition reactions to carbon - carbon double bonds like epoxidation and dihydroxylation.

A Cycloaddition is a pericyclic reaction in which the net result is loss of two pi bonds and gain of two sigma bonds. ... Due to Rolf Huisgens contribution to 1,3-dipolar cycloaddition chemistry, 1,3-dipolar cycloadditions are also named Huisgen Cycloadditions. ... The Diels-Alder reaction is an organic chemical reaction (specifically, a cycloaddition) between a conjugated diene and a substituted alkene, commonly termed the dienophile to form a substituted cyclohexene system. ... In chemistry, nucleophilic substitution is a class of substitution reaction in which an electron-rich nucleophile attacks a molecule and replaces a group or atom, called the leaving group. ... In chemistry a molecule experiences strain when in a chemical conformation there exist unfavorable bond angles or bond distances. ... Epoxy or polyepoxide is a thermosetting epoxide polymer that cures when mixed with a catalyzing agent or hardener. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. The first commercial attempts to prepare resins from epichlorohydrin occurred in 1927 in the United States. ... Aziridine parent compound Aziridines are a group of organic compounds sharing the aziridine functional group which is a three membered heterocycle with one amine group and two methylene groups 1,2. ... Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Non-proprietary Names (rINN) in use in Europe. ... In chemistry, an amide is either the organic functional group characterized by a carbonyl group linked to a nitrogen atom, a compound that contains this functional group, or a particular inorganic anion. ... An aldol reaction takes the following form: 2 enolate anions ↔ aldol The reaction requires a base catalyst. ... An addition reaction, in chemistry, is in its simplest terms a organic reaction where two or more molecules combine to form a larger one. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... An epoxide is a cyclic ether with only three ring atoms. ... Sharpless bishydroxylation or asymmetric dihydroxylation (AD) is a chemical reaction of an alkene with osmium tetroxide to form a diol (dialcohol). ...

References

• Click Chemistry: Diverse Chemical Function from a Few Good Reactions Hartmuth C. Kolb, M. G. Finn, K. Barry Sharpless Angewandte Chemie International Edition Volume 40, 2001, P. 2004 abstract
• W.C. Guida et al. Med. Res. Rev. p 3 1996