Aroyl halides synthesis

Various organotin reagents react with acyl and aroyl halides under mild conditions without decarbonylation to give carbonyl compounds[390,39l]. Alkyl- or alkenyltin reagents react with acyl and aroyl chlorides to give ketones[548.733,734]. One example is the preparation of the a,/3-dnsaturated 7-keto esters 860 and 861, carried out under a CO atmosphere[735]. The reaction has been applied intramolecularly to the synthesis of the macrocyclic keto... 

Instead of alkylating reagents, the use of acyl or aroyl halides in fhis reaction conveniently leads to the synthesis of selenoesters as useful acylating reagents in organic synthesis. A mild and convenient method is reaction of trimethylsilyl selenides with acyl halides [27] or reaction of selenols with imidazolide (or triazolide) of carboxylic acids (Scheme 15.8) [28]. 

The decarbonylation of aldehydes, acyl halides, aroyl halides, alcohols, or ketones is a useful and important reaction in organic synthesis/ Although several methods not utilizing transition metals are known " (including various deformylation reactions and thermal and photochemical decarbonylatlons), they are not general and not usually applicable under mild conditions where undesirable side reactions are minimized/ ... 

The varied uses of highly dipolar cyano-substituted quinodi-methanes has stimulated much synthetic interest as shown above, especially in the preparation of aryl-substituted malononitriles as potential precursors. A three-step synthesis of these compounds has been developed without use of arylation methodology (cf. above). Aroyl halides were treated sequentially with cyanotri-methylsilane and POCl - both in the presence of pyridine - to... 

In 1980, Detty and co-worker revealed the synthesis of selenol esters by the reaction of thallous phenyl selenide with aroyl and acyl halides (Eq. 35) [70]. 

The coupling of diazonium halides with suitable halogenated activated methylene groups is an excellent method of synthesis of a variety of acyl and aroyl hydrazidoyl halides. This method has been used by Favrel and by Dieckmann and Platz to synthesize the acetyl derivative (IV). 

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