Davis oxidation - Biblioteka.sk

Upozornenie: Prezeranie týchto stránok je určené len pre návštevníkov nad 18 rokov!
Zásady ochrany osobných údajov.
Používaním tohto webu súhlasíte s uchovávaním cookies, ktoré slúžia na poskytovanie služieb, nastavenie reklám a analýzu návštevnosti. OK, súhlasím


Panta Rhei Doprava Zadarmo
...
...


A | B | C | D | E | F | G | H | CH | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

Davis oxidation
 ...
Davis oxidation
Named after Franklin A. Davis
Reaction type Organic redox reaction
Identifiers
Organic Chemistry Portal davis-oxidation

In organic chemistry, the Davis oxidation or Davis' oxaziridine oxidation refers to oxidations involving the use of the Davis reagent (2-(phenylsulfonyl)-3-phenyloxaziridine) or other similar oxaziridine reagents.[1] This reaction mainly refers to the generation of α-hydroxy carbonyl compounds (acyloins) from ketones or esters.[2][3] 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.[4]

Other oxidations carried out by Davis' reagent include the oxidation of sulfides and selenides to sulfoxides[5][6] and selenoxides[7] without further oxidation; the oxidation of alkenes to epoxides;[8][9][10] and the oxidation of amines to hydroxylamines and amine oxides.[11]

Mechanism

Regarding the α-hydroxylation of carbonyls, the base first converts the ketone or ester into its corresponding enolate. Then, the enolate anion as a nucleophile attacks the oxygen atom of the oxaziridine in a SN2 mechanism, forming a hemiaminal intermediate. The intermediate then fragments into a sulfinimine, and, after protonation, the desired α-hydroxyketone or α-hydroxyester.[3][12][13]

See also

References

  1. ^ Kürti, László; Czakó, Barbara (29 September 2005). Strategic Applications of Named Reactions in Organic Synthesis. pp. 130–131. ISBN 978-0-12-429785-2.
  2. ^ Davis, Franklin A.; Vishwakarma, Lal C.; Billmers, Joanne G.; Finn, John (1 August 1984). "Synthesis of α-hydroxycarbonyl compounds (acyloins): direct oxidation of enolates using 2-sulfonyloxaziridines". The Journal of Organic Chemistry. 49 (17): 3241–3243. doi:10.1021/jo00191a048.
  3. ^ a b Davis, Franklin A.; Chen, Bang Chi (1992). "Asymmetric hydroxylation of enolates with N-sulfonyloxaziridines". Chemical Reviews. 92 (5): 919–934. doi:10.1021/cr00013a008.
  4. ^ Evans, David Albert; Morrissey, Michael M.; Dorow, Roberta L. (1985-07-01). "Asymmetric oxygenation of chiral imide enolates. A general approach to the synthesis of enantiomerically pure α-hydroxy carboxylic acid synthons". Journal of the American Chemical Society. 107 (14): 4346–4348. doi:10.1021/ja00300a054.
  5. ^ Mata, Ernesto G. (1996). "Recent advances in the synthesis of sulfoxides from sulfides". Phosphorus, Sulfur, and Silicon and the Related Elements. 117 (1): 231–286. doi:10.1080/10426509608038790.
  6. ^ Bohé, Luis; Lusinchi, Marie; Lusinchi, Xavier (1999). "Oxygen atom transfer from a chiral N-alkyl oxaziridine promoted by acid. The asymmetric oxidation of sulfides to sulfoxides". Tetrahedron. 55 (1): 155–156. doi:10.1016/S0040-4020(98)01035-7.
  7. ^ Davis, Franklin A.; Stringer, Orum D.; Billmers, Joanne M. (1983). "Oxidation of selenides to selenoxides using 2-sulfonyloxaziridines". Tetrahedron Letters. 24 (12): 1213–1216. doi:10.1016/S0040-4039(00)81617-2.
  8. ^ Davis, Franklin A.; Abdul-Malik, Nadia F.; Awad, Sami B.; Harakal, Mark E. (1981). "Epoxidation of olefins by oxaziridines". Tetrahedron Letters. 22 (10): 917–920. doi:10.1016/0040-4039(81)89008-9.
  9. ^ Davis, Franklin A.; Harakal, Mark E.; Awad, Sami B. (1983). "Chemistry of oxaziridines. 4. Asymmetric epoxidation of unfunctionalized alkenes using chiral 2-sulfonyloxaziridines: evidence for a planar transition state geometry". Journal of the American Chemical Society. 105 (10): 3123–3126. doi:10.1021/ja00348a029.
  10. ^ Bohé, Luis; Lusinchi, Marie; Lusinchi, Xavier (1999). "Oxygen atom transfer from a chiral oxaziridinium salt. Asymmetric epoxidation of unfunctionalized olefins". Tetrahedron. 55 (1): 141–154. doi:10.1016/S0040-4020(98)01034-5.
  11. ^ Zajac, Walter W. Jr.; Walters, Thomas R.; Darcy, Michael G. (1988). "Oxidation of amines with 2-sulfonyloxaziridines (Davis' reagents)". The Journal of Organic Chemistry. 53 (25): 5856–5860. doi:10.1021/jo00260a012.
  12. ^ Davis, Franklin A.; Sheppard, Aurelia C.; Chen, Bang Chi; Haque, M. Serajul (1990). "Chemistry of oxaziridines. 14. Asymmetric oxidation of ketone enolates using enantiomerically pure (camphorylsulfonyl)oxaziridine". Journal of the American Chemical Society. 112 (18): 6679–6690. doi:10.1021/ja00174a035.
  13. ^ Davis, Franklin A.; Weismiller, Michael C.; Murphy, Christopher K.; Reddy, R. Thimma; Chen, Bang Chi (1992). "Chemistry of oxaziridines. 18. Synthesis and enantioselective oxidations of the oxaziridines". The Journal of Organic Chemistry. 57 (26): 7274–7285. doi:10.1021/jo00052a050.


Zdroj:https://en.wikipedia.org?pojem=Davis_oxidation
Text je dostupný za podmienok Creative Commons Attribution/Share-Alike License 3.0 Unported; prípadne za ďalších podmienok. Podrobnejšie informácie nájdete na stránke Podmienky použitia.






Text je dostupný za podmienok Creative Commons Attribution/Share-Alike License 3.0 Unported; prípadne za ďalších podmienok.
Podrobnejšie informácie nájdete na stránke Podmienky použitia.

Your browser doesn’t support the object tag.

www.astronomia.sk | www.biologia.sk | www.botanika.sk | www.dejiny.sk | www.economy.sk | www.elektrotechnika.sk | www.estetika.sk | www.farmakologia.sk | www.filozofia.sk | Fyzika | www.futurologia.sk | www.genetika.sk | www.chemia.sk | www.lingvistika.sk | www.politologia.sk | www.psychologia.sk | www.sexuologia.sk | www.sociologia.sk | www.veda.sk I www.zoologia.sk