Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carboxylation, the addition of CO2 to a compound. Enzymes that catalyze decarboxylations are called decarboxylases or, the more formal term, carboxy-lyases (EC number 4.1.1).
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis.
Diethyl malonate, also known as DEM, is the diethyl ester of malonic acid. It occurs naturally in grapes and strawberries as a colourless liquid with an apple-like odour, and is used in perfumes. It is also used to synthesize other compounds such as barbiturates, artificial flavourings, vitamin B1, and vitamin B6.
The Pauson–Khand (PK) reaction is a chemical reaction, described as a [2+2+1] cycloaddition. In it, an alkyne, an alkene, and carbon monoxide combine into a α,β-cyclopentenone in the presence of a metal-carbonyl catalyst Ihsan Ullah Khand (1935–1980) discovered the reaction around 1970, while working as a postdoctoral associate with Peter Ludwig Pauson (1925–2013) at the University of Strathclyde in Glasgow. Pauson and Khand's initial findings were intermolecular in nature, but the reaction has poor selectivity. Some modern applications instead apply the reaction for intramolecular ends.
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).
The Hunsdiecker reaction is a name reaction in organic chemistry whereby silver salts of carboxylic acids react with a halogen to produce an organic halide. It is an example of both a decarboxylation and a halogenation reaction as the product has one fewer carbon atoms than the starting material and a halogen atom is introduced its place. A catalytic approach has been developed.
Dimethyl oxalate is an organic compound with the formula (CO2CH3)2 or (CH3)2C2O4. It is the dimethyl ester of oxalic acid. Dimethyl oxalate is a colorless or white solid that is soluble in water.
2,6-Lutidine is a natural heterocyclic aromatic organic compound with the formula (CH3)2C5H3N. It is one of several dimethyl-substituted derivative of pyridine, all of which are referred to as lutidines. It is a colorless liquid with mildly basic properties and a pungent, noxious odor.
BOP (benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate) is a reagent commonly used for the synthesis of amides from carboxylic acids and amines in peptide synthesis. It can be prepared from 1-hydroxybenzotriazole and a chlorophosphonium reagent under basic conditions. This reagent has advantages in peptide synthesis since it avoids side reactions like the dehydration of asparagine or glutamine redisues. BOP has used for the synthesis of esters from the carboxylic acids and alcohols. BOP has also been used in the reduction of carboxylic acids to primary alcohols with sodium borohydride (NaBH4). Its use raises safety concerns since the carcinogenic compound HMPA is produced as a stoichiometric by-product.
The Fukuyama coupling is a coupling reaction taking place between a thioester and an organozinc halide in the presence of a palladium catalyst. The reaction product is a ketone. This reaction was discovered by Tohru Fukuyama et al. in 1998.
Selenoxide elimination is a method for the chemical synthesis of alkenes from selenoxides. It is most commonly used to synthesize α,β-unsaturated carbonyl compounds from the corresponding saturated analogues. It is mechanistically related to the Cope reaction.
In organosulfur chemistry, thiosulfinate is a functional group consisting of the linkage R-S(O)-S-R. Thiolsulfinates are also named as alkanethiosulfinic acid esters.
Nitrile anions is jargon from the organic product resulting from the deprotonation of alkylnitriles. The proton(s) α to the nitrile group are sufficiently acidic that they undergo deprotonation by strong bases, usually lithium-derived. The products are not anions but covalent organolithium complexes. Regardless, these organolithium compounds are reactive toward various electrophiles.
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.
Desulfonylation reactions are chemical reactions leading to the removal of a sulfonyl group from organic compounds. As the sulfonyl functional group is electron-withdrawing, methods for cleaving the sulfur–carbon bonds of sulfones are typically reductive in nature. Olefination or replacement with hydrogen may be accomplished using reductive desulfonylation methods.
The Barton decarboxylation is a radical reaction in which a carboxylic acid is converted to a thiohydroxamate ester. The product is then heated in the presence of a radical initiator and a suitable hydrogen donor to afford the decarboxylated product. This is an example of a reductive decarboxylation. Using this reaction it is possible to remove carboxylic acid moieties from alkyl groups and replace them with other functional groups. This reaction is named after its developer, the British chemist and Nobel laureate Sir Derek Barton (1918–1998).
Diethyl oxomalonate is the diethyl ester of mesoxalic acid (ketomalonic acid), the simplest oxodicarboxylic acid and thus the first member (n = 0) of a homologous series HOOC–CO–(CH2)n–COOH with the higher homologues oxalacetic acid (n = 1), α-ketoglutaric acid (n = 2) and α-ketoadipic acid (n = 3) (the latter a metabolite of the amino acid lysine). Diethyl oxomalonate reacts because of its highly polarized keto group as electrophile in addition reactions and is a highly active reactant in pericyclic reactions such as the Diels-Alder reactions, cycloadditions or ene reactions. At humid air, mesoxalic acid diethyl ester reacts with water to give diethyl mesoxalate hydrate and the green-yellow oil are spontaneously converted to white crystals.
Corey–Nicolaou macrolactonization is a named reaction of organic chemistry, for the synthesis of lactones from hydroxy acids, found in 1974. The reaction uses 2,2'-dipyridyldisulfide and triphenylphosphine as reagents and runs in polar aprotic solvent under mild conditions.
In organic chemistry, the Davis oxidation or Davis' oxaziridine oxidation refers to oxidations involving the use of the Davis reagent or other similar oxaziridine reagents. This reaction mainly refers to the generation of α-hydroxy carbonyl compounds (acyloins) from ketones or esters. The reaction is carried out in a basic environment to generate the corresponding enolate from the ketone or ester. This reaction has been shown to work for amides.
Jiro Tsuji was a Japanese chemist, notable for his discovery of organometallic reactions, including the Tsuji-Trost reaction, the Tsuji-Wilkinson decarbonylation, and the Tsuji-Wacker reaction.
