Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene. Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents.
The aldol reaction is a reaction in organic chemistry that combines two carbonyl compounds to form a new β-hydroxy carbonyl compound. Its simplest form might involve the nucleophilic addition of an enolized ketone to another:
In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers. They have also been applied in asymmetric synthesis in the pharmaceutical industry. Due to the large difference in electronegativity between the carbon atom and the lithium atom, the C−Li bond is highly ionic. Owing to the polar nature of the C−Li bond, organolithium reagents are good nucleophiles and strong bases. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric.
The Suzuki reaction or Suzuki coupling is an organic reaction that uses a palladium complex catalyst to cross-couple a boronic acid to an organohalide. It was first published in 1979 by Akira Suzuki, and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their contribution to the discovery and development of noble metal catalysis in organic synthesis. This reaction is sometimes telescoped with the related Miyaura borylation; the combination is the Suzuki–Miyaura reaction. It is widely used to synthesize polyolefins, styrenes, and substituted biphenyls.
The Bamford–Stevens reaction is a chemical reaction whereby treatment of tosylhydrazones with strong base gives alkenes. It is named for the British chemist William Randall Bamford and the Scottish chemist Thomas Stevens Stevens (1900–2000). The usage of aprotic solvents gives predominantly Z-alkenes, while protic solvent gives a mixture of E- and Z-alkenes. As an alkene-generating transformation, the Bamford–Stevens reaction has broad utility in synthetic methodology and complex molecule synthesis.
The Hiyama coupling is a palladium-catalyzed cross-coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon–carbon bonds. This reaction was discovered in 1988 by Tamejiro Hiyama and Yasuo Hatanaka as a method to form carbon-carbon bonds synthetically with chemo- and regioselectivity. The Hiyama coupling has been applied to the synthesis of various natural products.
The Bouveault aldehyde synthesis is a one-pot substitution reaction that replaces an alkyl or aryl halide with a formyl group using a N,N-disubstituted formamide. For primary alkyl halides this produces the homologous aldehyde one carbon longer. For aryl halides this produces the corresponding carbaldehyde. The Bouveault aldehyde synthesis is an example of a formylation reaction, and is named for French scientist Louis Bouveault.
The Bouveault–Blanc reduction is a chemical reaction in which an ester is reduced to primary alcohols using absolute ethanol and sodium metal. It was first reported by Louis Bouveault and Gustave Louis Blanc in 1903. Bouveault and Blanc demonstrated the reduction of ethyl oleate and n-butyl oleate to oleyl alcohol. Modified versions of which were subsequently refined and published in Organic Syntheses.
The Curtius rearrangement, first defined by Theodor Curtius in 1885, is the thermal decomposition of an acyl azide to an isocyanate with loss of nitrogen gas. The isocyanate then undergoes attack by a variety of nucleophiles such as water, alcohols and amines, to yield a primary amine, carbamate or urea derivative respectively. Several reviews have been published.
In stereochemistry, a chiral auxiliary is a stereogenic group or unit that is temporarily incorporated into an organic compound in order to control the stereochemical outcome of the synthesis. The chirality present in the auxiliary can bias the stereoselectivity of one or more subsequent reactions. The auxiliary can then be typically recovered for future use.
The Blaise ketone synthesis is the chemical reaction of acid chlorides with organozinc compounds to give ketones.
Grignard reagents or Grignard compounds are chemical compounds with the general formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH3 and phenylmagnesium bromide (C6H5)−Mg−Br. They are a subclass of the organomagnesium compounds.
Schwartz's reagent is the common name for the organozirconium compound with the formula (C5H5)2ZrHCl, sometimes called zirconocene hydrochloride or zirconocene chloride hydride, and is named after Jeffrey Schwartz, a chemistry professor at Princeton University. This metallocene is used in organic synthesis for various transformations of alkenes and alkynes.
The Negishi coupling is a widely employed transition metal catalyzed cross-coupling reaction. The reaction couples organic halides or triflates with organozinc compounds, forming carbon-carbon bonds (C-C) in the process. A palladium (0) species is generally utilized as the catalyst, though nickel is sometimes used. A variety of nickel catalysts in either Ni0 or NiII oxidation state can be employed in Negishi cross couplings such as Ni(PPh3)4, Ni(acac)2, Ni(COD)2 etc.
Organozinc chemistry is the study of the physical properties, synthesis, and reactions of organozinc compounds, which are organometallic compounds that contain carbon (C) to zinc (Zn) chemical bonds.
The Liebeskind–Srogl coupling reaction is an organic reaction forming a new carbon–carbon bond from a thioester and a boronic acid using a metal catalyst. It is a cross-coupling reaction. This reaction was invented by and named after Jiri Srogl from the Academy of Sciences, Czech Republic, and Lanny S. Liebeskind from Emory University, Atlanta, Georgia, USA. There are three generations of this reaction, with the first generation shown below. The original transformation used catalytic Pd(0), TFP = tris(2-furyl)phosphine as an additional ligand and stoichiometric CuTC = copper(I) thiophene-2-carboxylate as a co-metal catalyst. The overall reaction scheme is shown below.
Tropic acid is a chemical with IUPAC name 3-hydroxy-2-phenylpropanoic acid and condensed structural formula HOCH2CHPhCOOH. It is a laboratory reagent used in the chemical synthesis of atropine and hyoscyamine. Tropic acid is a chiral substance, existing as either a racemic mixture or as a single enantiomer.
Electrophilic amination is a chemical process involving the formation of a carbon–nitrogen bond through the reaction of a nucleophilic carbanion with an electrophilic source of nitrogen.
An insertion reaction is a chemical reaction where one chemical entity interposes itself into an existing bond of typically a second chemical entity e.g.:
In organometallic chemistry, metal–halogen exchange is a fundamental reaction that converts an organic halide into an organometallic product. The reaction commonly involves the use of electropositive metals and organochlorides, bromides, and iodides. Particularly well-developed is the use of metal–halogen exchange for the preparation of organolithium compounds.
