Palladium-Catalyzed C(sp³)–H Nitrooxylation of Aliphatic Carboxamides with Practical Oxidants

Abstract

Here we report the palladium-catalyzed β-C(sp 3 )−H nitrooxylation of aliphatic carboxamides using a modified quinoline auxiliary. Notably, Al(NO 3 ) 3 •9H 2 O was used as a nitrate source as well as a practical oxidant. The 5-chloro-8-aminoquinoline auxiliary was nitrated in situ during the reaction, which may enhance its directing ability and help its removal. The reaction has a broad substrate scope with a variety of aliphatic carboxamides. The multiple substituted auxiliary can be easily removed and recovered. Two C−Hinsertion palladacycle intermediates were isolated and characterized to elucidate the mechanism.