Quinones, Friedel-Crafts acylation

Schiel, C., M. Oelgemoller, J. Ortner and J. Mattay, Green Photochemistry The Solar-Chemical Photo-Friedel-Crafts Acylation Of Quinones, Green Chemistry, 3, 224-228 (2001). 

Ortner, J., and Mattay, J. (2001) Green photochemistry the solar-chemical Photo-Friedel-Crafts acylation of quinones. Green Chemistry, 3, 224—228 ... 

Ketcha DM, Gribble GW (1985) A convenient synthesis of 3-acylindoles via Friedel Crafts acylation of l-(phenylsulfonyl)indole. A new route to pyridocarbazole-5, 11-quinones and ellipticme. J Org Chem 50 5451-5457... 

Derivatives of anthracene are seldom prepared from anthracene itself, but rather by ring-closure methods. As in the case of naphthalene, the most important method of ring closure involves adaptation of Friedel-Crafts acylation. The products initially obtained are anthraquinones, which can be converted into corresponding anthracenes by reduction with zinc and alkali. This last step is seldom carried out, since the quinones are by far the more important class of compounds. 

During the total synthesis of phomazarin, D.L. Boger and co-workers closed the B ring of the natural product with a Friedel-Crafts acylation reaction." This key step provided the fully functionalized phomazarin skeleton. The carboxylic acid precursor was exposed to trifluoroacetic anhydride at 50 °C for 72h. The initial product was a C5 trifluoroacetate, which was subsequently hydrolyzed in the presence of air, which oxidized the phenol to the corresponding B-ring quinone. 

Oelgemoller, M., Mattay, J., The Photochemical Friedel Crafts Acylation of Quinones from the Beginnings of Organic Photochemistry to Modem Solar Chemical Applications. In Horspool, W. M., Lenci, F. (eds), CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn, CRC Press LLC, Boca Raton, FL, 2004, Chapter 88, pp. 1 16. 

The "Photochemical Friedel-Crafts Acylation" of Quinones From the Beginnings of... 

From 1992, Kraus and co-workers explored the synthetic value of the photochemical acylation of 1,4-quinones (Scheme 32 Table 88.11), and developed it as a suitable alternative to existing thermal Friedel-Crafts acylations.During their studies on the pyranoquinone skeleton, they initially used the classical Friedel-Crafts approach but the poor solubUity of some of the starting materials, the drastic reaction... 

Following the original protocols described by Kraus,Mattay and co-workers examined numerous photoacylations of 1,4-quinones for which they introduced the term Photo-Friedel-Crafts acylation . In aU cases, the corresponding acylated products were obtained in moderate to good yields (Table 88.17). Because these authors were particularly interested in a large-scale solar chemical outdoor application of the acylation reaction, they replaced the toxic solvents (benzene or acetonitrile) with nontoxic f-butyl alcohol. 

J., and Mattay, J., Green photochemistry the solar-chemical photo-Friedel-Crafts acylation of quinones, Green Chem., 3, 224-228, 2001 (e) Oelgemoller, M., Schiel, C., Mattay, J., and Frbhlich, R., The photo-Friedel-Crafts acylation of 1,4-naphthoquinones, Eur. J. Org. Chem., 2465-2474, 2002 (f) Oelgemoller, M., Schiel, C., Ortner, J., and Mattay, J., The solarchemical Photo-Friedel-Crafts acylation of quinones in AG Solar Nordrhein-Westfalen — Solare Chemie und Solare... 

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