title: Metal-free radical 5-exo-dig cyclizations of phenol-linked 1,6-enynes for the synthesis of carbonylated benzofurans.
abstract: A new metal-free radical 5-exo-dig cyclization of phenol-linked 1,6-enynes with O2, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), and tBuONO is described. With this general method, carbonylated benzofurans can be accessed through incorporation of two oxygen atoms into the product from O2 and TEMPO through dioxygen activation and oxidative cleavage of the N-O bond, respectively.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China).
authors.forename: Ming
authors.initials: M
authors.lastname: Hu
authors.forename: Ren-Jie
authors.initials: RJ
authors.lastname: Song
authors.forename: Jin-Heng
authors.initials: JH
authors.lastname: Li
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis*; D003500:Cyclization; D008670:Metals / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*
chemical_list: D001572:Benzofurans; D008670:Metals; D010636:Phenols
keywords: benzofurans; cyclization; dioxygen activation; enynes; radical reactions