433-19-2Relevant articles and documents
Synthesis and reductive elimination of arylPd(II) trifluoromethyl complexes: A remarkable concentration effect on chemoselectivity
Zhang, Song-Lin,Deng, Zhu-Qin
, p. 32664 - 32667 (2016)
Reductive elimination from Pd(II) aryl trifluoromethyl complexes is a challenging and elusive step which is accompanied by a number of kinetically more favorable side reactions giving rising to a complex mixture. We report herein the synthesis and isolation of several arylPd(II) trifluoromethyl complexes (2a-c) and study their electronic structures, photophysical properties and reductive elimination reactivities. A remarkable concentration effect on chemoselectivity is observed for thermal decomposition of (Xantphos)Pd(II)(Ar)(CF3) (2c) that favors the formation of Ar-CF3 at lower concentrations, but gives increasingly more Ar-Ar homocoupling product to a dominant extent as the concentration of 2c increases. This is solid evidence for the involvement of an intermolecular Ar/CF3 ligand exchange/Ar-Ar reductive elimination mechanism that has been proposed based on DFT computational studies. The interplay between theory and experiment provides valuable insights into the mechanism and kinetics of the key elementary reaction of reductive elimination at Pd(II), and may thus prompt the design of more efficient Pd-mediated nucleophilic trifluoromethylation reactions.
Isolation of OH-bridged Ag(i)/Cu(iii) and ion-pair Cu(i)/Cu(iii) trifluoromethyl complexes with monophosphines
Xiao, Chang,Zhang, Song-Lin
supporting information, p. 848 - 853 (2019/01/21)
Cu(iii)-CF3 complexes are important intermediates of both synthetic and mechanistic interest. This study describes the isolation, and spectroscopic and X-ray crystallographic characterization of CuIII-CF3 complexes 2-4 with typical monophosphine ligands PPh3 and Buchwald-type biarylmonophosphines. Distinct from the ion-pair [P2Cu(i)]+[Cu(iii)(CF3)4]? structures of 2 and 4 (P: PPh3 or SPhos), complex 3 exhibits a novel OH-bridged Ag(i)-Cu(iii) dinuclear structure with XPhos-coordinated linear Ag(i) and square planar Cu(iii) components. This is the first heterobimetallic Cu(iii)-CF3 complex confirmed by both solution-phase NMR spectroscopy and solid state X-ray crystal structure analysis. Complex 3 is found to have the LUMO orbital of major σ*(Cu-CF3) nature and electrophilic CF3 ligands. Accordingly, complex 3 is able to trifluoromethylate 2 equivalents of aryl boronic acids in up to quantitative yields, regardless of the inert or oxidative conditions. In contrast, the ion-pair complexes 2 and 4 show low reactivity. This study enriches the coordination and reactivity chemistry of Cu(iii)-CF3 compounds and shows the feasibility of modulation of structures and reactivity by ligand design, which may inspire future efforts on Cu(iii)-CF3 chemistry.
Diverse copper(iii) trifluoromethyl complexes with mono-, bi- and tridentate ligands and their versatile reactivity
Zhang, Song-Lin,Xiao, Chang,Wan, Hai-Xing
supporting information, p. 4779 - 4784 (2018/04/11)
Cu(iii) trifluoromethyl complexes are proposed as essential intermediates for many copper-promoted trifluoromethylation reactions, but remain elusive and scarcely explored. We report herein the isolation and spectroscopic and X-ray crystallographic charac
