title: Ligand free copper(I)-catalyzed synthesis of diaryl ether with Cs2CO3 via a free radical path.
abstract: Complexes [Cu(I)(2,4-dimethylphenoxy)2](-) (A) and [Cu(II)(2,4-dimethylphenoxy)2(p-tolyl)](-) (B) were observed by in situ electrospray ionization mass spectrometry (ESI-MS) analysis of the ligand free copper(I)-catalyzed C-O coupling reaction using Cs2CO3 under the catalytic reaction conditions indicating that they could be intermediates in the reaction. The radical scavenger cumene retarded the reaction. Catalytic cycles involving a free radical path are proposed based on these observations.
authors.affiliation: Institute of Chemistry, Academia Sinica, 128 Academia Road Sec. 2, Nankang, Taipei 115, Taiwan, Republic of China. sgshyu@chem.sinica.edu.tw.
authors.forename: Hong-Jie
authors.initials: HJ
authors.lastname: Chen
authors.forename: Mei-Chun
authors.initials: MC
authors.lastname: Tseng
authors.forename: I-Jui
authors.initials: IJ
authors.lastname: Hsu
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Chen
authors.forename: Chien-Chung
authors.initials: CC
authors.lastname: Han
authors.forename: Shin-Guang
authors.initials: SG
authors.lastname: Shyu