title: Reversed-polarity synthesis of diaryl ketones via palladium-catalyzed cross-coupling of acylsilanes.
abstract: Acylsilanes serve as acyl anion equivalents in a palladium-catalyzed cross-coupling reaction with aryl bromides to give unsymmetrical diaryl ketones. Water plays a unique and crucial activating role in these reactions. High-throughput experimentation techniques provided successful reaction conditions initially involving phosphites as ligands. Ultimately, 1,3,5,7-tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane was identified as giving a longer-lived catalyst with higher turnover numbers. Its use, in conjunction with a palladacycle precatalyst, led to optimal reaction rates and yields. Scope and limitations of this novel method are presented along with initial mechanistic insight.
authors: Penn/Merck Laboratory for High-Throughput Experimentation, Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
authors: Jason R
authors: JR
authors: Schmink
authors: Shane W
authors: SW
authors: Krska
mesh_terms: D001965:Bromides / Q000737:chemistry; D002384:Catalysis; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*
chemical_list: D001965:Bromides; D007659:Ketones; D012821:Silanes; D010165:Palladium