Directing-Group-Free Palladium-Catalyzed C-H Arylation of Aldoxime Using Oxime's Umpolung Properties.

Alkyl aldoximes without a directing group undergo palladium-catalyzed C-H arylation with aryl bromides to afford alkyl aryl ketoximes in moderate to high yields. The reaction of electron-rich aryl bromides and linear oximes proceeded to afford the coupling products in up to 98% yield. This reaction has broad scope and excellent functional group tolerance. Although reactions using hydroxyl oximes as nucleophiles have generally proceeded on the oxygen atom, this reaction selectively proceeds on oxime carbons by taking advantage of the oxime's umpolung properties and Pd reactivity.