2694-78-2Relevant articles and documents
Gas phase carbon and deuterium isotope effects on electron affinity of benzophenone: A combined experimental and theoretical study
Yamataka, Hiroshi,Mishima, Masaaki,Kuwatani, Yoshiyuki,Tsuno, Yuho
, p. 5829 - 5831 (1995)
Carbonyl-13C, 17O, and C6D5 isotope effects (IEs) on the electron transfer equilibrium between benzophenone and benzophenone radical anion were determined by means of fourier transfer ion cyclotron resonance (FT-ICR) measurements and the ab initio MO calculations (UHF/6-31G*). The experimental and theoretical IEs are in excellent agreement with each other (K12/K13 = 1.03 (50°C, ICR), 1.026 (50°C, MO) and KD5/KH5 = 1.35 (50°C, ICR), 1.325 (50°C, MO)). The carbonyl-13C, 17O, ring 13C12, and D10 IEs were calculated as 1.044, 1.025, 1.206, and 2.812, respectively, at -75°C. The carbonyl-13C and 17O IEs disagree with the reported IEs in liquid NH3 (K12/K13 = 2.0, K16//K17 = 0.26, at -75°C, Stevenson et al. J. Phys. Chem. 1988, 92, 3687) and are close to unity as generally expected. The present results do not support the explanation in terms of an ion association effect in the liquid phase.
Iron-Carbonyl-Catalyzed Redox-Neutral [4+2] Annulation of N-H Imines and Internal Alkynes by C-H Bond Activation
Jia, Teng,Zhao, Chongyang,He, Ruoyu,Chen, Hui,Wang, Congyang
supporting information, p. 5268 - 5271 (2016/04/26)
Stoichiometric C-H bond activation of arenes mediated by iron carbonyls was reported by Pauson as early as in 1965, yet the catalytic C-H transformations have not been developed. Herein, an iron-catalyzed annulation of N-H imines and internal alkynes to furnish cis-3,4-dihydroisoquinolines is described, and represents the first iron-carbonyl-catalyzed C-H activation reaction of arenes. Remarkablely, this is also the first redox-neutral [4+2] annulation of imines and alkynes proceeding by C-H activation. The reaction also features only cis stereoselectivity and excellent atom economy as neither base, nor external ligand, nor additive is required. Experimental and theoretical studies reveal an oxidative addition mechanism for C-H bond activation to afford a dinuclear ferracycle and a synergetic diiron-promoted H-transfer to the alkyne as the turnover-determining step. Double dose of iron: The titled redox-neutral [4+2] annulations to furnish cis-3,4-dihydroisoquinolines were achieved by using iron catalysis. Mechanistic studies show the synergy of dinuclear iron in the C-H bond activation and turnover-limiting hydrogen-transfer steps. The reaction demonstrates excellent atom economy and exclusive cis stereoselectivity.
Ir(III)-Catalyzed Synthesis of Isoquinoline N-Oxides from Aryloxime and α-Diazocarbonyl Compounds
Phatake, Ravindra S.,Patel, Pitambar,Ramana, Chepuri V.
supporting information, p. 292 - 295 (2016/02/03)
An efficient Ir(III)-catalyzed C-H activation and annulations of aryloxime with α-diazocarbonyl compounds has been developed for the synthesis of substituted isoquinoline N-oxides. The reaction proceeds under mild atmospheric conditions, without any external oxidants and releases N2 and H2O as the byproducts. In addition, synthetic applications of the N-oxide products have been established by performing further functionalization. An interesting dimeric iridacyclic complex allied through a bis-silver carboxylate bridge has been isolated that efficiently catalyzed the reaction.
