Ketones aromatic, synthesis of

The most important method for the synthesis of aromatic ketones 3 is the Friedel-Crafts acylation. An aromatic substrate 1 is treated with an acyl chloride 2 in the presence of a Lewis-acid catalyst, to yield an acylated aromatic compound. Closely related reactions are methods for the formylation, as well as an alkylation procedure for aromatic compounds, which is also named after Friedel and Crafts. 

An ingenious strategy developed by Jun s group makes use of a chelating 3-picolin-2-yl group for performing C-C bond forming reactions. In the particular example shown, for the synthesis of aromatic ketones, methylvinyl ketone is added to suppress unwanted reductive amination processes (Equation (130)). 

The Pd-catalyzed reaction of simple arenes and nitriles provides a useful synthesis of aromatic ketones.120 The reaction of toluene and benzonitrile in the presence of Pd(OAc)2 as a catalyst in DMSO and TFA gives diarylketones (Equation (92)). The presence of DMSO is essential in this reaction. 

In this paper we report the use of supported heteropoly acid (silicotungstic acid) and supported phosphoric acid catalysts for the acylation of industrially relevant aromatic feedstocks with acid anhydrides in the synthesis of aromatic ketones. In particular, we describe the acylation of thioanisole 1 with iso-butyric anhydride 2 to form 4-methyl thiobutyrophenone 3. The acylation of thioanisole with acetic anhydride has been reported in which a series of zeolites were used as catalysts. Zeolite H-beta was reported to have the highest activity of the zeolites studied (41 mol % conversion, 150°C) (2). 

Synthesis of aromatic ketones from carboxylic acid derivatives (Expts 6.126 and 6.127). 

SYNTHESIS OF AROMATIC KETONES FROM CARROXYLIC ACID DERIVATES... 

Bezouhanova, C. P. Synthesis of aromatic ketones in the presence of zeolite catalysts, Appl. Catal., A, 2002, 229, 127-133. 

Friedel-Crafts acylation Synthesis of aromatic ketones using acyl halides or anhydrides. 176... 

Houben-Hoesch reaction Synthesis of aromatic ketones from activated aromatic compounds (e.g. phenols) and nitriles. 216... 

Hoesch, K. A new synthesis of aromatic ketones. I. Preparation of some phenol ketones. Ber. 1915,48, 1122-1133. 

Bigi, F., Maggi, R., Sartori, G., Casnati, G., Bocelli, G. Template Houben-Hoesch reaction on metal phenolates. Synthesis of aromatic ketones, nitriles and amides. Crystal structure of dichloro[2-(1-imino-2,2,2-trichloroethyl)-4-methoxyphenoxido-0,N]boron. Gazz. Chim. Ital. 

Synthesis of Aromatic Ketone-Derived Hydrazone-Based mPEG-HZ-PE Conjugates... 

Thus these very simple reactions are easily handled on a large scale from current starting materials and constitute a good way for the synthesis of aromatic ketones, particularly of the 93 type. 

Mikolajczyk, M., Grzejszczak, S., Chefezynska, A., and Zatorski, A., Addition of elemental sulfur to phosphonate carbanions and its application for the synthesis of a-phosphoryl organosulfur compounds. Synthesis of aromatic ketones, J. Org. Chem., 44, 2967, 1979. 

Smith, K., Zhenhua, Z., and Hodgson, P. K. G. 1998. Synthesis of aromatic ketones by acylation of aryl ethers with carboxylic anhydrides in the presence of zeolite H- 3 (H-BEA) in the absence of solvent. /. Mol. Catal. A Chem. 134 121-128. 

Deutsch, J., Trunschke, A., Muller, D., Quaschning, V., Kemnitz, E., and Lieske, H. 2003. Different acylating agents in the synthesis of aromatic ketones on sulfated zirconia. Catal. Lett. 88 9-15. 

Helping readers to better understand the mechanism of the Friedel-Crafts acylation, the examples in the book substantiate the development of more effective catalysts and more selective processes achieved during the last few decades, enabling industry to embark on a safer and more efficient synthesis of aromatic ketones for the manufacture of a wide array of products. 

The Friedel - Crafts aromatic acylation (Eq. 1) and related Fries rearrangement of aryl esters, e.g. phenyl acetate (Eq. 2 Ac = acetyl), catalysed by strong acids are the most important routes for the synthesis of aromatic ketones that are intermediates in manufacturing fine and speciality chemicals as well as pharmaceuticals. ... 

Synthesis of aromatic ketones, including those derived from mononitro-benzenes, can be achieved in good yields (60-90%) by using controlled-potential electro-oxidation of the corresponding o -complexes [25]. These o -complexes are formed (yields from 50 to 100%) with an excess of ketone and a strong base... 

Transition metal-catalyzed reductive acylation, coupHng, amination, and cycHzation reactions of oximes and their derivatives 13CJ066. Transition-metal-catalyzed synthesis of aromatic ketones via direct C—H bond activation 12S677. 

Synthesis of Aromatic Ketones (Friedel-Crafts Acylation)... 

Finally, don t forget that acid chlorides are used in the synthesis of aromatic ketones through Friedel-Crafts acylation (p. 643).This very useful reaction is shown in Figure 18.28. 

The polymerization of a,P-unsaturated carbonyl compounds is very similar to the Friedel-Crafts synthesis of aromatic ketones, where tiie catalyst forms a complex with the reaction products and therefore is necessarily to be used in equimolecular amount. In order to avoid the WCle consumption via doping of polyacetylenes we tried to perform COER with highly substituted olefins (tetraphenylethylene, stylbene, 1,1-diphenylethylene) and simple carbonyl compounds (benzophenone, terephthalaldehyde) using WClfunctional groups are in different molecules and the results should be new olefins and new carbonyl compounds, not a conjugated... 

Zhao, J., Hughes, C.O. and Toste, F.D. (2006) Synthesis of aromatic ketones by a transition metal-catalyzed tandem sequence. Journal of the American Chemical Society, 128(23), 7436-7437. 

---