Ketones bearing an α, β-aryl or -hetaryl substituent

A comprehensive review of the aromatic ketone preparations, since 1995, is described. New methods include catalytic Friedel"Crafts acylations using a variety of new catalysts that replace traditional reactions that use molar equivalents of Lewis acid; however, reactions using carboxylic acids, esters, and the Houben"Hoesch reaction are still mediated by common Brønsted and Lewis acids. Alternative electrophilic acylations of organometallics include new mild organocopper and gallium reagents. Weinreb amides remain popular for acylation of organolithium and Grignard reagents. Examples of palladium-catalyzed cross-couplings of organotin, zinc, and boron reagents with acid derivatives, and activated carboxylic acids with organoborons are described. Carbon monoxide is used in transition metal-mediated carbonylative cross-couplings and acyl radical preparations. Hydroacylations that directly convert arylaldehydes into arylketones, and numerous recent oxidations of benzylic methylenes, alcohols, and double bonds to aromatic ketones are reviewed. Less frequent oxidations, and new reductions of arylesters into ketones are included. Fries-rearrangements include the preparation of 2-hydroxyarylketones directly from the free phenol or naphthol without prior isolation of the ester. Other preparations of phenolic, various substituted, and polycyclic aryl ketones are described. Significant advances in the preparation of ketones substituted onto furan, pyrrole, indole, pyridine, and miscellaneous heterocycles are described.