Copper-catalyzed aerobic nitrogen-migration cyanation and oxygenation of unsaturated ketoximes via the CC bond cleavage: facile access to 4-oxobutanenitriles†
Abstract
A new copper-catalyzed aerobic synthesis of 4-oxobutanenitriles by the nitrogen-migration cyanation and oxygenation of γ,δ-unsaturated ketoximes at room temperature is developed. By means of a copper(0) powder catalyst, the nitrogen-migration cyanation and oxygenation of unsaturated ketoximes with O2via a radical intramolecular 5-exo-trig cyclization, CC double bond cleavage and ring-opening process efficiently execute to assemble 4-oxobutanenitriles. Mechanistic studies indicate that these processes include radicals initiating the reaction from the oxime side and the superoxide radical formation.