The Friedel–Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877 to attach substituents to an aromatic ring. Friedel–Crafts reactions are of two main types: alkylation reactions and acylation reactions. Both proceed by electrophilic aromatic substitution.
The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide called a Wittig reagent. Wittig reactions are most commonly used to convert aldehydes and ketones to alkenes. Most often, the Wittig reaction is used to introduce a methylene group using methylenetriphenylphosphorane (Ph3P=CH2). Using this reagent, even a sterically hindered ketone such as camphor can be converted to its methylene derivative.
The Reformatsky reaction is an organic reaction which condenses aldehydes or ketones with α-halo esters using metallic zinc to form β-hydroxy-esters:
The McMurry reaction is an organic reaction in which two ketone or aldehyde groups are coupled to form an alkene using a titanium chloride compound such as titanium(III) chloride and a reducing agent. The reaction is named after its co-discoverer, John E. McMurry. The McMurry reaction originally involved the use of a mixture TiCl3 and LiAlH4, which produces the active reagents. Related species have been developed involving the combination of TiCl3 or TiCl4 with various other reducing agents, including potassium, zinc, and magnesium. This reaction is related to the Pinacol coupling reaction which also proceeds by reductive coupling of carbonyl compounds.
The Peterson olefination is the chemical reaction of α-silyl carbanions with ketones to form a β-hydroxysilane (2) which eliminates to form alkenes (3).
In organic chemistry, an α-halo ketone is a functional group consisting of a ketone group or more generally a carbonyl group with an α-halogen substituent. α-Halo ketones are alkylating agents. Prominent α-halo ketones include phenacyl bromide and chloroacetone.
Chromium(II) chloride describes inorganic compounds with the formula CrCl2(H2O)n. The anhydrous solid is white when pure, however commercial samples are often grey or green; it is hygroscopic and readily dissolves in water to give bright blue air-sensitive solutions of the tetrahydrate Cr(H2O)4Cl2. Chromium(II) chloride has no commercial uses but is used on a laboratory-scale for the synthesis of other chromium complexes.
The Petasis reagent, named after Nicos A. Petasis, is an organotitanium compound with the formula Cp2Ti(CH3)2. It is an orange-colored solid.
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.
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 Stork enamine alkylation involves the addition of an enamine to a Michael acceptor or another electrophilic alkylation reagent to give an alkylated iminium product, which is hydrolyzed by dilute aqueous acid to give the alkylated ketone or aldehyde. Since enamines are generally produced from ketones or aldehydes, this overall process constitutes a selective monoalkylation of a ketone or aldehyde, a process that may be difficult to achieve directly.
The Nozaki–Hiyama–Kishi reaction is a nickel/chromium coupling reaction forming an alcohol from the reaction of an aldehyde with an allyl or vinyl halide. In their original 1977 publication, Tamejiro Hiyama and Hitoshi Nozaki reported on a chromium(II) salt solution prepared by reduction of chromic chloride by lithium aluminium hydride to which was added benzaldehyde and allyl chloride:
The Nysted reagent is a reagent used in organic synthesis for the methylenation of a carbonyl group. It was discovered in 1975 by Leonard N. Nysted in Chicago, Illinois. It was originally prepared by reacting dibromomethane and activated zinc in THF. A proposed mechanism for the methenylation reaction runs as follows:
Organomanganese chemistry is the chemistry of organometallic compounds containing a carbon to manganese chemical bond. In a 2009 review, Cahiez et al. argued that as manganese is cheap and benign, organomanganese compounds have potential as chemical reagents, although currently they are not widely used as such despite extensive research.
In organic chemistry, carbonyl reduction is the conversion of any carbonyl group, usually to an alcohol. It is a common transformation that is practiced in many ways. Ketones, aldehydes, carboxylic acids, esters, amides, and acid halides - some of the most pervasive functional groups, -comprise carbonyl compounds. Carboxylic acids, esters, and acid halides can be reduced to either aldehydes or a step further to primary alcohols, depending on the strength of the reducing agent. Aldehydes and ketones can be reduced respectively to primary and secondary alcohols. In deoxygenation, the alcohol group can be further reduced and removed altogether by replacement with H.
Reductions with samarium(II) iodide involve the conversion of various classes of organic compounds into reduced products through the action of samarium(II) iodide, a mild one-electron reducing agent.
In organic chemistry, a vinyl iodide functional group is an alkene with one or more iodide substituents. Vinyl iodides are versatile molecules that serve as important building blocks and precursors in organic synthesis. They are commonly used in carbon-carbon forming reactions in transition-metal catalyzed cross-coupling reactions, such as Stille reaction, Heck reaction, Sonogashira coupling, and Suzuki coupling. Synthesis of well-defined geometry or complexity vinyl iodide is important in stereoselective synthesis of natural products and drugs.
Organotantalum chemistry is the chemistry of chemical compounds containing a carbon-to-tantalum chemical bond. A wide variety of compound have been reported, initially with cyclopentadienyl and CO ligands. Oxidation states vary from Ta(V) to Ta(-I).
Tamejiro Hiyama is a Japanese organic chemist. He is best known for his work in developing the Nozaki-Hiyama-Kishi reaction and the Hiyama coupling. He is currently a professor at the Chuo University Research and Development Initiative, and a Professor Emeritus of Kyoto University.
Carbonyl olefin metathesis is a type of metathesis reaction that entails, formally, the redistribution of fragments of an alkene and a carbonyl by the scission and regeneration of carbon-carbon and carbon-oxygen double bonds respectively. It is a powerful method in organic synthesis using simple carbonyls and olefins and converting them into less accessible products with higher structural complexity.
