title: Ruthenium-catalyzed oxidative coupling/cyclization of isoquinolones with alkynes through C-H/N-H activation: mechanism study and synthesis of dibenzo[a,g]quinolizin-8-one derivatives.
abstract: The mechanism of [{RuCl(2)(p-cymene)}(2)]-catalyzed oxidative annulations of isoquinolones with alkynes was investigated in detail. The first step is an acetate-assisted C-H bond activation process to form cyclometalated compounds. Subsequent mono-alkyne insertion of the Ru-C bonds of the cyclometalated compounds then takes place. Finally, oxidative coupling of the C-N bond of the insertion compounds occurs to afford Ru(0) sandwich complexes that undergo oxidation to regenerate the catalytically active Ru(II) complex with the copper oxidant and release the desired dibenzo[a,g]quinolizin-8-one derivatives. All of the relevant intermediates were fully characterized and determined by single crystal X-ray diffraction analysis. The [{RuCl(2)(p-cymene)}(2)]-catalyzed C-H bond functionalization of isoquinolones with alkynes to synthesize dibenzo[a,g]quinolizin-8-one derivatives through C-H/N-H activation was also demonstrated.
authors.affiliation: State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, PR China. nklibin@nankai.edu.cn
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Huiliang
authors.initials: H
authors.lastname: Feng
authors.forename: Nuancheng
authors.initials: N
authors.lastname: Wang
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Ma
authors.forename: Haibin
authors.initials: H
authors.lastname: Song
authors.forename: Shansheng
authors.initials: S
authors.lastname: Xu
authors.forename: Baiquan
authors.initials: B
authors.lastname: Wang
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D007546:Isoquinolines / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D011807:Quinolizines / Q000138:chemical synthesis* / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry
chemical_list: D000480:Alkynes; D007546:Isoquinolines; D009942:Organometallic Compounds; D011807:Quinolizines; C579461:dibenzo(a,g)quinolizin-8-one; D012428:Ruthenium