# Structural Biochemistry/Organic Chemistry/Reagents

A reagent is an inorganic or small organic molecule that helps the reactant react in a chemical reaction.

## List of Reagents, Its Uses and Information

* AIBN [azobis (isobutyronitrile)] is used for radical initiator. AIBN is a white acicular crystal, which is insolvable in water, solvable in organic solvent such as methyl alcohol, ethanol, acetone, ethyl ether and light petroleum etc. Ice point of pure product is 105 degree Celsius. The product is decomposed flashily and it releases nitrogen gas in the position of melting. It decomposes slowly under ordinary temperature, which should be stored under 20 degree Celsius. AIBN is maily used as polymerization initiator of monomer such as chloroethylene, vinyl acetate,acrylonitrile, etc. Also, it is used as blowing agent for PVC, polyalkene, polyurethane, polyvinyl alcohol, acrylonitrile/butadiene copolymer, chloroethylene copolymer, acrylonitrile/ butadiene/styrene copolymer, polyisocyanate, polyvinyl acetate, polyamide and polyester, etc. Moreover, it is also used in other organic synthesis.
* AlCl$_3$ (aluminum trichloride) is used for Lewis acid catalyst. It is a yellowish or grayish-white, crystalline powder with a sharp oodor. It is used as a chemical intermediate for Aluminum compounds, as a catalyst for cracking petroleum, in preserving wood, and in medications, disinfectants, cosmetics, photography and textiles.
* BF$_3$ (boron trifluoride) is used for Lewis acid catalyst of chemical reactions. It is a colorless gas with a pungent odor. It reacts readily to form coordination complexes with molecules having at least one pair of unshared electrons.
* BH$_3$ (borane) is used for hydroboration. Borane-lewis base complexes are often found in literature. Borane-tetrahydrofuran (BTHF) and borane-dimethyl sulfide (BMS, DMSB) are often used as a borane source. Both reagents are available in solution (e.g. 1 M in THF), and are therefore easier to handle than diborane. Volatility and flammability are always a drawback. BMS is more stable than BTHF but has an unpleasant odor.
* Br$_2$ (bromine) is used for radical bromination and dibromination. Bromine compounds are used as pesticides, dyestuffs, water purification compounds, and as a flame-retardants in plastics. 1,2-dibromoethane is used as an anti-knock agent to raise the octane number of gasoline and allow engines to run more smoothly. This application has declined as a result of environmental legislation. Potassium bromide is used as a source of bromide ions for the manufacture of silver bromide for photographic film.
* CCl$_4$ (carbon tetrachloride) is used for nonpolar inert solvent. It is a manufactured chemical that does not occur naturally. It is a clear liquid with a sweet smell that can be detected at low levels. It is also called carbon chloride, methane tetrachloride, perchloromethane, tetrachloroethane, or benziform. Carbon tetrachloride is most often found in the air as a colorless gas. It is not flammable and does not dissolve in water very easily. It was used in the production of refrigeration fluid and propellants for aerosol cans, as a pesticide, as a cleaning fluid and degreasing agent, in fire extinguishers, and in spot removers. Because of its harmful effects, these uses are now banned and it is only used in some industrial applications.
* CHCl$_3$ (chloroform) is used for polar, nonflammable solvent. It is also a highly volatile, clear, colourless, heavy, and highly refractive.
* CH$_2$Cl$_2$ (dichloromethane) is used for polar, nonflammable solvent. Chloroform has a relatively narrow margin of safety and has been replaced by better inhalation anesthetics. In addition, it is believed to be toxic to the liver and kidneys and may cause liver cancer. Chloroform was once widely used as a solvent, but safety and environmental concerns have reduced this use as well. Nevertheless, chloroform has remained an important industrial chemical.
* CH$_2$I$_2$ (diiodomethane) is used for Simmons-Smith cyclopropanation. It is a colorless liquid. It decomposes upon exposure to light liberating iodine, which colours samples brownish.
* CH$_2$N$_2$ (diazomethane) is used for making methyl esters from acid and cyclopropanation. It is not only toxic but also potentially explosive.
* DIBAL (diisobutylaluminum) is used for selective reduction of esters, amides, and nitriles to aldehydes.
* Dicycolhexylborane is used for hydroboration of alkyne derivatives and anti-Markovnikov hydration.
* Dioxane is used for good solvent for dissolving water and organic substrates. It is a colorless liquid with a faint sweet odor similar to that of diethyl ether. It is classified as an ether.
* DMD (dimethyldioxirane) is used for epoxidation of alkenes. It is the most commonly used dioxirane in organic synthesis, and can be considered as a monomer of acetone peroxide.
* DMF (dimethylformamide) is used for polar aprotic solvent. This colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions.
* DMSO (dimethylsulfoxide) is use for polar aprotic solvent. This colorless liquid is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water.
* Et$_2$O (diethyl ether) is used for medium polarity solvent. It is a colorless, highly volatile flammable liquid with a characteristic odor.
* FeBr$_3$ (iron tribromide) is used for Lewis acid catalyst in the halogenation of aromatic compounds.
* H$_2$ (hydrogen) is used for hydrogenation and reduction of nitro. Hydrogen is the only element that can exist without neutrons. Hydrogen’s most abundant isotope has no neutrons. Hydrogen forms both positive and negative ions. It does this more readily than any other element. It is the most abundant element in the universe. Hydrogen is the only atom for which the Schrödinger equation has an exact solution. Moreover, it reacts explosively with the elements oxygen, chlorine and fluorine: O2, Cl2, F2.
* H$_2$O$_2$ (hydrogen peroxide) is used for oxidative workup of hydroboration. It is used to help stop infection in cuts or scrapes, we can use it as a mouthwash when diluted with water, and it is also used to bleach hair.
* Hg(OAc)$_2$ (mercuric acetate) is used for oxymercuriation. Mercuric Acetate can affect in berating and by passing through skin. Also, mercuric acetate should be handled as a teratogen with extreme caution. Mercury poisoning can cause "shakes", irritability, sore gums. It increased saliva, personality change and permanent brain or kidney damage. Mercury accumulates in the body.
* HgSO$_4$ (mercuric sulfate) is used for Markovnikov hydration of alkynes. It is an odorless solid that forms white granules or crystalline powder. In water, it separates into an insoluble sulfate with a yellow color and sulfuric acid.
* HIO$_4$ (metaperiodic acid) is used for oxidative cleavage of 1,2-diols. In dilute aqueous solution, periodic acid exists as discrete hydronium and metaperiodate ions.
* HMPA (hexamethylphosphoramide) is used for preventing aggregation (polar aprotic solvent). It is a phosphoramide having the formula [2N]3PO.
* K$_2$Cr$_2$O$_7$/H$_2$SO$_4$ (potassium dichromate) is used in oxidation of alcohols. (Jones Reagent)
* LAH (lithium aluminum hydride) is used for very strong hydride source and reduces esters to alcohols. It is an inorganic compound with the chemical formula LiAlH4.
* LiAl(Ot-Bu)$_3$H [lithium tri(t-butoxy) aluminum hydride] is used for modified hydride source and reduces acid chlorides to aldehydes.
* LDA (lithium diisopropylamide) is used for strong, hindered base.
* Lindlar's catalyst is used for reducing alkynes to cis-alkenes.
* mCPBA (m-chlroperbenzoic acid) is used for epoxidation of alkenes.
* MnO$_2$ (manganese dioxide) is used for selective oxidation of allylic alcohols.
* MsCl [methanesulfonyl chloride(mesyl chloride)] is used for converting hydroxyl to a good LG.
* NaBH$_4$ (sodium borohydride) is used for mild source of hydride. It is an inorganic compound.
* NaBH$_3$CN (sodium cyanoborohydride) is used for reductive amination and hydride source stable to mild acid.
* NaNO$_2$ (sodium nitrite) is used for diazotization of amines. Sodium nitrite is a salt and an anti-oxidant that is used to cure meats like ham, bacon and hot dogs. Sodium nitrite serves a vital public health function: it blocks the growth of botulism-causing bacteria and prevents spoilage. It is also gives cured meats their characteristic color and flavor. Also, USDA-sponsored research indicates that sodium nitrite can help prevent the growth of Listeria monocytogenes, an environmental bacterium that can cause illness in some at-risk populations.
* NBS (N-bromosuccinimide) is used for bromine surrogate. It is a brominating and oxidizing agent that is used as source for bromine in radical reactions. For example: allylic brominations and various electrophilic additions. The NBS bromination of substrates such as alcohols and amines, followed by elimination of HBr in the presence of a base, leads to the products of net oxidation in which no bromine has been incorporated.
* n-BuLi is used for strong base.
* NCS (N-chlorosuccinimide) is used for chlorine surrogate.
* O$_3$ (ozone) is used for oxidative cleavage of alkenes. It is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope, breaking down with a half life.
* OsO$_4$ (osmium tetroxide) is used for dihydroxylation of alkenes.
* PCC (pyridinium chlorochromate) is used for selective oxidation of primary alcohols to aldehydes.
* PPH $_3$ (triphenylphosphine) is used for making Wittig reagents.
* SOCl$_2$ (thionyl chloride) is used for converting alcohols to alkyl chlorides.
* THF (tetrahydrofuran) is used for medium polarity solvent.
* pTsCl [p-toluenesulfonyl chloride (tosyl chloride)] is used for converting hydroxyl to a good LG.
* pTsOH [p-toluenesulfonic acid (tosic acid)] is used for oragnic-soluble source of strong acid.
* Zn(Hg) (zinc amalgam) is used for Clemmensen reduction (with HCl).
* Jones Reagent (CrO3, H2SO4, H2O) is a solution of chromium trioxide in diluted sulfuric acid that can be used safely for oxidations of organic substrates.
* SOCL2 - forms alkyl chlorides from alcohols
* Clemmensen Reduction (Zn(Hg), HCl) - removes a ketone and replaces it with hydrogens.
* Grinard reagents (R-Mg-X) - an organometalic chemical reaction where an alkyl-magnesium halide is added to a carbonyl group in an aldehyde or ketone.

## References

* http://en.wikipedia.org/wiki/Reagent
* http://www.reagents.com/
* http://www.chem.wisc.edu/areas/reich/handouts/namereagents/namedreag.htm