title: One-Pot Synthesis of Benzene-Fused Medium-Ring Ketones: Gold Catalysis-Enabled Enolate Umpolung Reactivity.
abstract: Enolate umpolung reactivities offer valuable and potentially unique alternatives over the enolate counterparts for the construction of ubiquitous carbonyl compounds. We disclose here that N-alkenoxypyridinium salts, generated readily upon gold-catalyzed additions of protonated pyridine N-oxide to C-C triple bonds of unactivated terminal alkynes, display versatile enolate umpolung chemistry upon heating and react with tethered arene nucleophiles in an SN2' manner. In a synthetically efficient one-pot, two-step process, this chemistry enables expedient preparation of valuable benzo-fused seven-/eight-membered cyclic ketones, including those of O-/N-heterocycles, from easily accessible aryl-substituted linear alkyne substrates. The reaction yields can be up to 87%.
authors.affiliation: Department of Chemistry & Biochemistry, University of California , Santa Barbara, California 93106, United States.|Department of Chemistry, Xuzhou Medical College , Xuzhou, China 221004.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Chemistry & Biochemistry, University of California , Santa Barbara, California 93106, United States.
authors.forename: Hongyi
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Chemistry & Biochemistry, University of California , Santa Barbara, California 93106, United States.
authors.forename: Zhixun
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Chemistry & Biochemistry, University of California , Santa Barbara, California 93106, United States.|Taizhou University , Taizhou, Zhejiang, China 317000.
authors.forename: Anguo
authors.initials: A
authors.lastname: Ying
authors.affiliation: Department of Chemistry & Biochemistry, University of California , Santa Barbara, California 93106, United States.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhang
mesh_terms: D001554:Benzene / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006046:Gold / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D007659:Ketones; D006046:Gold; D001554:Benzene