title: Reactivity of [K₃(phen)₈][Cu(NPh₂)₂]₃--a possible intermediate in the copper(I)-catalyzed N-arylation of N-phenylaniline.
abstract: Complex [K3(phen)8][Cu(NPh2)2]3 (1, phen = phenanthroline) was isolated from the catalytic C-N cross coupling reaction based on the CuI-phen-tBuOK catalytic system. Complex 1 can react with 4-iodotoluene to give 4-methyl-N,N-diphenylaniline (3a) in 50% yield (based on all available NPh2(-) ligands of complex 1). In addition, 1 can also work as an effective catalyst for the C-N coupling reactions under the same reaction conditions, indicating that 1 may be an effective intermediate of the catalytic system. In the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), a radical scavenger, the stoichiometric reaction between complex 1 and 4-iodotoluene was significantly quenched to give a low yield of 12%. The results suggest that the radical path dominates in the reaction, with (phen)KNPh2 as the possible radical source. The structures of 1 and (phen)KNPh2 were both determined by single crystal X-ray diffraction studies.
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Republic of China. sgshyu@gate.sinica.edu.tw.
authors.forename: Chia-Kai
authors.initials: CK
authors.lastname: Tseng
authors.forename: Chi-Rung
authors.initials: CR
authors.lastname: Lee
authors.forename: Mei-Chun
authors.initials: MC
authors.lastname: Tseng
authors.forename: Chien-Chung
authors.initials: CC
authors.lastname: Han
authors.forename: Shin-Guang
authors.initials: SG
authors.lastname: Shyu
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003497:Cyclic N-Oxides / Q000737:chemistry; D008968:Molecular Conformation; D010618:Phenanthrolines / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D056831:Coordination Complexes; D003497:Cyclic N-Oxides; D010618:Phenanthrolines; D003300:Copper; C023650:aniline; C003959:TEMPO