Carboxylation

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Carboxylation is a chemical reaction in which a carboxylic acid is produced by treating a substrate with carbon dioxide. [1] The opposite reaction is decarboxylation. In chemistry, the term carbonation is sometimes used synonymously with carboxylation, especially when applied to the reaction of carbanionic reagents with CO2. More generally, carbonation usually describes the production of carbonates. [2]

Contents

Organic chemistry

Carboxylation is a standard conversion in organic chemistry. [3] Specifically carbonation (i.e. carboxylation) of Grignard reagents and organolithium compounds is a classic way to convert organic halides into carboxylic acids. [4]

Sodium salicylate, precursor to aspirin, is commercially prepared by treating sodium phenolate (the sodium salt of phenol) with carbon dioxide at high pressure (100 atm) and high temperature (390 K) – a method known as the Kolbe-Schmitt reaction. Acidification of the resulting salicylate salt gives salicylic acid.

Kolbe-Schmitt.png

Many detailed procedures are described in the journal Organic Syntheses . [5] [6] [7]

Carboxylation catalysts include N-Heterocyclic carbenes [8] and catalysts based on silver. [9]

Carboxylation in biochemistry

Carbon-based life originates from carboxylation that couples atmospheric carbon dioxide to a sugar. The process is usually catalysed by the enzyme RuBisCO. Ribulose-1,5-bisphosphate carboxylase/oxygenase, the enzyme that catalyzes this carboxylation, is possibly the single most abundant protein on Earth. [10] [11] [12]

The Calvin cycle showing the carboxylation of ribulose-1,5-bisphosphate. Calvin-cycle4.svg
The Calvin cycle showing the carboxylation of ribulose-1,5-bisphosphate.
Carboxyglutamic acid Carboxyglutamic acid.svg
Carboxyglutamic acid

Many carboxylases, including Acetyl-CoA carboxylase, Methylcrotonyl-CoA carboxylase, Propionyl-CoA carboxylase, and Pyruvate carboxylase require biotin as a cofactor. These enzymes are involved in various biogenic pathways. [13] In the EC scheme, such carboxylases are classed under EC 6.3.4, "Other Carbon—Nitrogen Ligases".

Another example is the posttranslational modification of glutamate residues, to γ-carboxyglutamate, in proteins. It occurs primarily in proteins involved in the blood clotting cascade, specifically factors II, VII, IX, and X, protein C, and protein S, and also in some bone proteins. This modification is required for these proteins to function. Carboxylation occurs in the liver and is performed by γ-glutamyl carboxylase (GGCX). [14] GGCX requires vitamin K as a cofactor and performs the reaction in a processive manner. [15] γ-carboxyglutamate binds calcium, which is essential for its activity. [16] For example, in prothrombin, calcium binding allows the protein to associate with the plasma membrane in platelets, bringing it into close proximity with the proteins that cleave prothrombin to active thrombin after injury. [17]

See also

Related Research Articles

<span class="mw-page-title-main">Carboxylic acid</span> Organic compound containing a –C(=O)OH group

In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is R−COOH or R−CO2H, with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.

<span class="mw-page-title-main">Ketone</span> Organic compounds of the form >C=O

In organic chemistry, a ketone is a functional group with the structure R−C(=O)−R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group −C(=O)−. The simplest ketone is acetone, with the formula (CH3)2CO. Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids, and the solvent acetone.

In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These terms are commonly used in chemistry, biochemistry, soil science, and the biological sciences.

<span class="mw-page-title-main">RuBisCO</span> Key enzyme of the photosynthesis involved in carbon fixation

Ribulose-1,5-bisphosphate carboxylase/oxygenase, commonly known by the abbreviations RuBisCo, rubisco, RuBPCase, or RuBPco, is an enzyme involved in light-independent part of photosynthesis, including the carbon fixation by which atmospheric carbon dioxide is converted by plants and other photosynthetic organisms to energy-rich molecules such as glucose. It emerged approximately four billion years ago in primordial metabolism prior to the presence of oxygen on earth. It is probably the most abundant enzyme on Earth. In chemical terms, it catalyzes the carboxylation of ribulose-1,5-bisphosphate.

<span class="mw-page-title-main">Imine</span> Organic compound or functional group containing a C=N bond

In organic chemistry, an imine is a functional group or organic compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions.

<span class="mw-page-title-main">Ribulose 1,5-bisphosphate</span> Chemical compound

Ribulose 1,5-bisphosphate (RuBP) is an organic substance that is involved in photosynthesis, notably as the principal CO2 acceptor in plants. It is a colourless anion, a double phosphate ester of the ketopentose called ribulose. Salts of RuBP can be isolated, but its crucial biological function happens in solution. RuBP occurs not only in plants but in all domains of life, including Archaea, Bacteria, and Eukarya.

In organic chemistry, an acyl chloride is an organic compound with the functional group −C(=O)Cl. Their formula is usually written R−COCl, where R is a side chain. They are reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride, CH3COCl. Acyl chlorides are the most important subset of acyl halides.

<span class="mw-page-title-main">Dipeptide</span> Shortest peptide molecule, containing two amino acids joined by a single peptide bond

A dipeptide is an organic compound derived from two amino acids. The constituent amino acids can be the same or different. When different, two isomers of the dipeptide are possible, depending on the sequence. Several dipeptides are physiologically important, and some are both physiologically and commercially significant. A well known dipeptide is aspartame, an artificial sweetener.

In organic chemistry, a nitrile is any organic compound that has a −C≡N functional group. The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons.

<span class="mw-page-title-main">Acyl halide</span> Oxoacid compound with an –OH group replaced by a halogen

In organic chemistry, an acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group.

In chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical compound. Such compounds are termed acetate esters or simply acetates. Deacetylation is the opposite reaction, the removal of an acetyl group from a chemical compound.

<span class="mw-page-title-main">Carboxyglutamic acid</span> Chemical compound

Carboxyglutamic acid, is an uncommon amino acid introduced into proteins by a post-translational carboxylation of glutamic acid residues. This modification is found, for example, in clotting factors and other proteins of the coagulation cascade. This modification introduces an affinity for calcium ions. In the blood coagulation cascade, vitamin K is required to introduce γ-carboxylation of clotting factors II, VII, IX, X and protein Z.

<span class="mw-page-title-main">Calvin cycle</span> Light-independent reactions in photosynthesis

The Calvin cycle,light-independent reactions, bio synthetic phase,dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose. The Calvin cycle is present in all photosynthetic eukaryotes and also many photosynthetic bacteria. In plants, these reactions occur in the stroma, the fluid-filled region of a chloroplast outside the thylakoid membranes. These reactions take the products of light-dependent reactions and perform further chemical processes on them. The Calvin cycle uses the chemical energy of ATP and reducing power of NADPH from the light dependent reactions to produce sugars for the plant to use. These substrates are used in a series of reduction-oxidation reactions to produce sugars in a step-wise process; there is no direct reaction that converts several molecules of CO2 to a sugar. There are three phases to the light-independent reactions, collectively called the Calvin cycle: carboxylation, reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration.

The Kolbe–Schmitt reaction or Kolbe process is a carboxylation chemical reaction that proceeds by treating phenol with sodium hydroxide to form sodium phenoxide, then heating sodium phenoxide with carbon dioxide under pressure, then treating the product with sulfuric acid. The final product is an aromatic hydroxy acid which is also known as salicylic acid.

Palladium on carbon, often referred to as Pd/C, is a form of palladium used as a catalyst. The metal is supported on activated carbon to maximize its surface area and activity.

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.

Pivalic acid, also known as neovaleric acid, is a carboxylic acid with a molecular formula of (CH3)3CCO2H. This colourless, odiferous organic compound is solid at room temperature. A common abbreviation for the pivalyl or pivaloyl group (t-BuC(O)) is Piv and for pivalic acid (t-BuC(O)OH) is PivOH. It is an isomer of valeric acid, the other two isomers of it are 2-Methylbutanoic acid and 3-Methylbutanoic acid.

<span class="mw-page-title-main">Gamma-glutamyl carboxylase</span>

Gamma-glutamyl carboxylase is an enzyme that in humans is encoded by the GGCX gene, located on chromosome 2 at 2p12.

Metal carbon dioxide complexes are coordination complexes that contain carbon dioxide ligands. Aside from the fundamental interest in the coordination chemistry of simple molecules, studies in this field are motivated by the possibility that transition metals might catalyze useful transformations of CO2. This research is relevant both to organic synthesis and to the production of "solar fuels" that would avoid the use of petroleum-based fuels.

<span class="mw-page-title-main">1-Naphthoic acid</span> Chemical compound

1-Naphthoic acid is an organic compound of the formula C10H7CO2H. It is one of two isomeric monocarboxylic acids of naphthalene, the other one being 2-naphthoic acid. 1-Naphthoic acid is a frequent substrate for C-H activation reactions. In general the hydroxynaphthoic acids are far more useful than the parent. It can be prepared by carboxylation of the Grignard reagent generated from 1-Bromonaphthalene.

References

  1. "Carboxylation: The introduction of a carboxyl group into a molecule or compound to form a carboxylic acid or a carboxylate; an instance of this." Oxford English Dictionary. Oxford University Press. 2018.
  2. "Carbonation: Impregnation or treatment with carbon dioxide; conversion into a carbonate." Oxford English Dictionary. Oxford University Press. 2018.
  3. Braunstein, Pierre; Matt, Dominique; Nobel, Dominique (August 1988). "Reactions of Carbon Dioxide with Carbon-Carbon Bond Formation Catalyzed by Transition-Metal Complexes". Chemical Reviews. 88 (5): 747–764. doi:10.1021/cr00087a003.
  4. A. M. Appel; et al. (2013). "Frontiers, Opportunities, and Challenges in Biochemical and Chemical Catalysis of CO2 Fixation". Chem. Rev. 113 (8): 6621–6658. doi:10.1021/cr300463y. PMC   3895110 . PMID   23767781.
  5. Akira Yanagisawa; Katsutaka Yasue; Hisashi Yamamoto (1997). "Regio- and Stereoselective Carboxylation of Allylic Barium Reagents: (E)-4,8-Dimethyl-3,7-Nonadienoic Acid". Organic Syntheses. 74: 178. doi:10.15227/orgsyn.074.0178.
  6. H. Koch; W. Haaf (1964). "1-Adamantanecarboxylic Acid". Organic Syntheses. 44: 1. doi:10.15227/orgsyn.044.0001.
  7. W. Haaf (1966). "1-Methylcyclohexanecarboxylic Acid". Organic Syntheses. 46: 72. doi:10.15227/orgsyn.046.0072.
  8. Zhang Liang (2013). "N-Heterocyclic carbene (NHC)–copper-catalysed transformations of carbon dioxide". Chemical Science. 4 (9): 3395. doi:10.1039/C3SC51070K.
  9. K. Sekine; T. Yamada (2016). "Silver-catalyzed carboxylation". Chem. Soc. Rev. 45 (16): 4524–4532. doi: 10.1039/C5CS00895F . PMID   26888406.
  10. Dhingra A, Portis AR, Daniell H (April 2004). "Enhanced translation of a chloroplast-expressed RbcS gene restores small subunit levels and photosynthesis in nuclear RbcS antisense plants". Proc. Natl. Acad. Sci. U.S.A. 101 (16): 6315–20. Bibcode:2004PNAS..101.6315D. doi: 10.1073/pnas.0400981101 . PMC   395966 . PMID   15067115. (Rubisco) is the most prevalent enzyme on this planet, accounting for 30–50% of total soluble protein in the chloroplast;
  11. Feller U, Anders I, Mae T (2008). "Rubiscolytics: fate of Rubisco after its enzymatic function in a cell is terminated" (PDF). J. Exp. Bot. 59 (7): 1615–24. doi:10.1093/jxb/erm242. PMID   17975207.
  12. Raven, John A. (April 2013). "Rubisco: still the most abundant protein of Earth?". New Phytologist. 198 (1): 1–3. doi: 10.1111/nph.12197 . PMID   23432200.
  13. "Biotin – Fact Sheet for Health Professionals". Office of Dietary Supplements, US National Institutes of Health. 8 December 2017. Retrieved 25 February 2018.
  14. OMIM - gamma-glutamyl carboxylase, contributed by McKusick VA, last updated October 2004
  15. Morris DP, Stevens RD, Wright DJ, Stafford DW (1995). "Processive post-translational modification. Vitamin K-dependent carboxylation of a peptide substrate". J. Biol. Chem. 270 (51): 30491–8. doi: 10.1074/jbc.270.51.30491 . PMID   8530480.
  16. Hauschka PV, Lian JB, Gallop PM (1975). "Direct identification of the calcium-binding amino acid, gamma-carboxyglutamate, in mineralized tissue". Proc. Natl. Acad. Sci. U.S.A. 72 (10): 3925–9. Bibcode:1975PNAS...72.3925H. doi: 10.1073/pnas.72.10.3925 . PMC   433109 . PMID   1060074.
  17. Berg JM, Tymoczko JL, Stryer L. Biochemistry, 5th ed. New York: W. H. Freeman and Company, 2002.