Wolff rearrangement

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The Wolff rearrangement is a rearrangement reaction converting a α-diazo-ketone into a ketene.^[1][2][3] This reaction was first reported by L. Wolff in 1912.^[4]

The rearrangement is catalyzed by light^[5], heat^[6], 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.

In one application,^[7] 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.

[edit] References

1. ↑  Meier, H.; Zeller, K.-P. Angew. Chem. Int. Ed. Engl. 1975, 14, 32-43. (Review)
2. ↑  Gill, C. B. Comp. Org. Syn. 1991, 3, 887-912. (Review)
3. ↑  Kirmse, W. Eur. J. Org. Chem. 2002, 2002, 2193-2256. (Review)
4. ↑  Wolff, L. Ann. 1912, 394, 25.
5. ↑  Wheeler, T. N.; Meinwald, J. Org. Syn., Coll. Vol. 6, p.840 (1988); Vol. 52, p.53 (1972) (Article)
6. ↑  Smith, L. I.; Hoehn, H. H. Org. Syn., Coll. Vol. 3, p.356 (1955); Vol. 20, p.47 (1940) (Article)
7. ↑  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)