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In the related Hammick reaction, uncatalyzed decarboxylation of a picolinic acid gives a stable carbene that attacks a carbonyl electrophile. Oxidative decarboxylations are generally radical reactions. These include the Kolbe electrolysis and Hunsdiecker-Kochi reactions. The Barton decarboxylation is an unusual radical reductive decarboxylation.
The dry distillation of calcium acetate to give acetone was reported by Charles Friedel in 1858 [3] and until World War I ketonization was the premier commercial method for its production. [ 4 ] Ketonic decarboxylation of propanoic acid over a manganese(II) oxide catalyst in a tube furnace affords 3-pentanone .
In the absence of metal catalysts, decarbonylation (vs decarboxylation) is rarely observed in organic chemistry. One exception is the decarbonylation of formic acid: H CO OH → CO + H 2 O. The reaction is induced by sulfuric acid, which functions as both a catalyst and a dehydrating agent.
The Kolbe–Schmitt reaction proceeds via the nucleophilic addition of a phenoxide, classically sodium phenoxide (NaOC 6 H 5), to carbon dioxide to give the salicylate. The final step is the reaction (protonation) of the salicylate anion with an acid to form the desired salicylic acids (ortho- and para- isomers).
Studies of decarboxylation over nickel and palladium-based catalysts were first reported by Wilhelm Maier et al., in 1982, [6] when they achieved the deoxygenation of several carboxylic acids via decarboxylation under a hydrogen atmosphere. This included the conversion of aliphatic acids (such as heptanoic and octanoic acids) to alkanes (namely ...
Decarboxylation reaction reactions are typically quite thermodynamically favorable due to the entropic contribution of cleaving a single molecule into two, one of which is a gas. Conversely, we can expect carboxylation reactions to be energy-requiring, and we should not be surprised to learn ATP hydrolysis is coupled to carboxylation.
The Barton decarboxylation is a radical reaction in which a carboxylic acid is converted to a thiohydroxamate ester (commonly referred to as a Barton ester). The product is then heated in the presence of a radical initiator and a suitable hydrogen donor to afford the decarboxylated product.
Usually, they are named after the substrate whose decarboxylation they catalyze, for example pyruvate decarboxylase catalyzes the decarboxylation of pyruvate. Examples [ edit ]