Iron-catalyzed oxidative cyclization of olefinic 1,3-dicarbonyls with ketone C(sp3)–H bonds: facile access to 2,3-dihydrofurans†
Abstract
Iron-catalyzed oxidative cyclization of olefinic 1,3-dicarbonyls with ketone C(sp3)–H bonds through C–C and C–O bond formations has been described for the first time. A broad substrate scope and ease of scale-up are the attractive features of this synthetic method, which provides a series of potentially bioactive 2,3-dihydrofurans. The reaction pathway is proposed to involve a radical addition of the in situ formed α-carbonyl radical to the CC bond of olefinic 1,3-dicarbonyls followed by intramolecular 5-endo-trig cyclization.