Wolff rearrangement

Wolff rearrangement

The Wolff rearrangement is a rearrangement reaction converting a α-diazo-ketone into a ketene.Ref|Meier1975Ref|Gill1991Ref|Kirmse2002 This reaction was first reported by Ludwig Wolff in 1912.Ref|Wolff1912

The rearrangement is catalyzed by lightRef|Wheeler1972, heatRef|Smith1940, or a transition metal catalyst such as silver oxide. Nitrogen gas is expelled forming a carbenic intermediate which rearranges. This 1,2-rearrangement is the key step in the Arndt-Eistert synthesis.

The reaction may or may not proceed in a concerted mechanism. A carbene intermediate is avoided if the reaction proceeds through the concerted mechanism. Mechanistic studies have been aimed at determining if migration is concerted with loss of nitrogen. The conclusion that has emerged is that a carbene is generated in photochemical reactions but the reaction can be concerted under the thermal conditions.

In one application,Ref|Sudrik2006 the Wolff rearrangement is performed in an electrochemical setup in which the catalyst silver oxide is reduced to elemental silver in the shape of monodisperse nanoparticles (2-4 nm diameter) which trigger the decomposition of the diazoketone by the formation of a radical cation.

References

# Meier, H.; Zeller, K.-P. "Angew. Chem. Int. Ed. Engl." 1975, "14", 32-43. ( [http://www3.interscience.wiley.com/cgi-bin/abstract/106580169/ABSTRACT Review] )
# Gill, C. B. "Comp. Org. Syn." 1991, "3", 887-912. (Review)
# Kirmse, W. "Eur. J. Org. Chem." 2002, "2002", 2193-2256. ( [http://www3.interscience.wiley.com/cgi-bin/abstract/95515300/ABSTRACT Review] )
# Ludwig Wolff "Ann." 1912, "394", 25.
# Wheeler, T. N.; Meinwald, J. "Org. Syn.", Coll. Vol. 6, p.840 (1988); Vol. 52, p.53 (1972) ( [http://www.orgsynth.org/orgsyn/prep.asp?prep=cv6p0840 Article] )
# Smith, L. I.; Hoehn, H. H. "Org. Syn.", Coll. Vol. 3, p.356 (1955); Vol. 20, p.47 (1940) ( [http://www.orgsynth.org/orgsyn/prep.asp?prep=cv3p0356 Article] )
# "Wolff Rearrangement of -Diazoketones Using in Situ Generated Silver Nanoclusters as Electron Mediators" Surendra G. Sudrik, Jadab Sharma, Vilas B. Chavan, Nirmalya K. Chaki, Harikisan R. Sonawane, and Kunjukrishna P. Vijayamohanan "Org. Lett." 2006, "8(6)", 1089-1092. (DOI|10.1021/ol052981w)

External Links

# TalkChem.com Blogs ( [http://talkchem.com/blog/name-reactions/wolff-rearrangement.html] )


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Réarrangement de Wolff — Le réarrangement de Wolff est une réaction de réarrangement d une α diazo cétone en cétène[1],[2],[3]. Cette réaction a été décrite la première fois par Ludwig Wolff en 1912 …   Wikipédia en Français

  • Rearrangement reaction — A rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule.[1] Often a substituent moves from one atom to another atom in the same… …   Wikipedia

  • Wolff-Umlagerung — Die Wolff Umlagerung ist eine chemische Reaktion, bei der aus Diazoverbindungen mit einer Carbonylgruppe in Nachbarposition zur Diazogruppe Ketene erhalten werden:[1][2] Die Reaktion kann unter dem Einfluss von UV Strahlung photochemisch, durch… …   Deutsch Wikipedia

  • Reacción de Wolff — Saltar a navegación, búsqueda La reacción de Wolff es una reacción de reorganización que transforma una α diazo cetona en una cetena.[1] [2] [3] Esta reacción fue descrita por Ludwig Wolff en 1912 …   Wikipedia Español

  • 1,2-rearrangement — A 1,2 rearrangement or 1,2 migration or 1,2 shift or Whitmore 1,2 shift cite journal | title = The common basis of molecular rearrangements | first = Frank C. | last = Whitmore | journal = J. Am. Chem. Soc. | date = 1932 | volume = 54 | issue = 8 …   Wikipedia

  • Curtius rearrangement — The Curtius rearrangement (or Curtius reaction or Curtius degradation), as first defined by Theodor Curtius, is a chemical reaction that involves the rearrangement of an acyl azide to an isocyanate.[1][2] Several reviews have been… …   Wikipedia

  • Ludwig Wolff — Infobox Scientist name = Ludwig Wolff image width = caption = Ludwig Wolff birth date = birth date|1857|9|27 birth place = Neustadt an der Weinstraße Germany residence = nationality = German death date = death date and age|1919|2|24|1857|9|27… …   Wikipedia

  • Ludwig Wolff (chimiste) — Pour les articles homonymes, voir Ludwig Wolff. Ludwig Wolff (27 septembre 1857 à Neustadt an der Weinstraße – 24 février 1919 à Jena) est un chimiste allemand. Sommaire 1 Biographie 2 Recherc …   Wikipédia en Français

  • List of organic reactions — Well known reactions and reagents in organic chemistry include Contents: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z    See also   Ext …   Wikipedia

  • 1,3-déshydroadamantane — Propellane de gauche à droite : [1.1.1]propellane, [2.2.2]propellane, 1,3 dehydroadamantane Les propellanes sont une classe d hydrocarbures saturés ou alcanes tricycliques c est à dire avec deux atomes de carbone tête de pont et quatre… …   Wikipédia en Français

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”