Fluorides, acyl aryl, from

After insertion of CO, the resulting metal acyl complex could undergo a reductive elimination of RCOX. Alternatively, it may react with a variety of nucleophilic counterparts, which is what makes this chemistry so valuable in organic synthesis. Depending on the reaction media and the conditions, it is possible to synthesize acids, esters, amides, or acid fluorides from the same starting material, as shown in Scheme 2 for aryl-X compounds [16]. 

N-Formylsaccharin 102, an easily accessible crystalline compound, has been employed as an efficient CO source in Pd-catalyzed fluorocarbonyl-ation of aryl halides 103 to afford the corresponding acyl fluorides 104 (13OL5370). Reagent KF is expected to serve as a dual role not only as a nucleophile for Pd-catalyzed carbonylation but also as an activator for CO generation from 102. The reactions use a near-stoichiometric amount of the CO source (1.2 eq) and tolerate diverse functional groups. The acyl fluorides 104 can be readily transformed into various carboxylic acid derivatives such as carboxylic acid, esters, thioesters, and amides in a one-pot procedure. 

SCHEME 7.106 Acyl fluoride synthesis from aryl bromides [171]. 

Need to prepare an acyl fluoride from an aryl bromide... 

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