60344-91-4Relevant academic research and scientific papers
Rhodium(III)-Catalyzed ortho-Heteroarylation of Phenols through Internal Oxidative C-H Activation: Rapid Screening of Single-Molecular White-Light-Emitting Materials
Li, Bijin,Lan, Jingbo,Wu, Di,You, Jingsong
, p. 14008 - 14012 (2016/01/25)
Reported herein is the first example of a transition-metal-catalyzed internal oxidative C-H/C-H cross-coupling between two (hetero)arenes through a traceless oxidation directing strategy. Without the requirement of an external metal oxidant, a wide range of phenols, including phenol-containing natural products, can undergo the coupling with azoles to assemble a large library of highly functionalized 2-(2-hydroxyphenyl)azoles. The route provides an opportunity to rapidly screen white-light-emitting materials. As illustrative examples, two bis(triphenylamine)-bearing 2-(2-hydroxyphenyl)oxazoles, which are difficult to access otherwise, exhibit bright white-light emission, high quantum yield, and thermal stability. Also presented is the first example of the white-light emission, in a single excited-state intramolecular proton transfer system, of 2-(2-hydroxyphenyl)azoles, thus highlighting the charm of C-H activation in the discovery of new organic optoelectronic materials.
Titanium and zirconium catalysts with [N,O] ligands: Syntheses, characterization, and their catalytic properties for olefin polymerization
Shi, Xiao-Chao,Jin, Guo-Xin
, p. 7198 - 7205,8 (2020/09/02)
A series of titanium and zirconium complexes L2MCl2 bearing salicylbenzoxazole ligands 2-(5-R-benzoxazol-2-yl)-6-R 1-4-R2-phenol (L) (2a, M = Ti, R1 = R 2 = tBu, R = H; 2j, M = Ti, R1 = cumyl, R 2 = tBu, R = H; 2k, M = Ti, R1 = Ad, R 2 = tBu, R = H; 3a, M = Zr, R1 = R2 = tBu, R = H; 3b, M = Zr, R1 = R2 = tBu, R = CH3; 3c, M = Zr, R1 = R2 = tBu, R = tBu; 3d, M = Zr, R1 = R2 = tBu, R = Cl; 3e, M = Zr, R1 = R2 = tBu, R = NO2; 3f, M = Zr, R1 = H, R2 = H, R = H; 3g, M = Zr, R1 = CH3, R2 = H, R = H; 3h, M = Zr, R1 = tBu, R2 = H, R = H; 3i, M = Zr, R1 = tBu, R2 = CH3, R = H; 3j, M = Zr, R1 = cumyl, R2 = tBu, R = H; 3k, M = Zr, R1 = Ad, R2 = tBu, R = H) were synthesized. All the ligands and the metal complexes were fully characterized by 1H and 13C NMR spectra and elemental analyses. The molecular structures of 3b,d,i,j were determined by single-crystal X-ray diffraction methods. Upon activation with methylaluminoxane (MAO), the zirconium complexes 3a-e,h-k bearing a bulky substitute on the ortho position of the phenol ring show high activities for ethylene polymerization and produced high-molecular-weight polyethylenes. For the titanium complexes, only trace polymers were obtained on activatation with MAO. The oligomerization of 1-hexene was also conducted by the zirconium complexes 3a-k, but only low molecular weights and stereoirregular oligomers were obtained.
