35875-81-1Relevant academic research and scientific papers
Highly efficient AgNO3-catalyzed approach to 2-(benzo[d]azol-2-yl)phenols from salicylaldehydes with 2-aminothiophenol, 2-aminophenol and benzene-1,2-diamine
He, Xinwei,Wu, Yuhao,Jin, Wenjing,Wang, Xiaoshun,Wu, Cong,Shang, Yongjia
, (2018/02/13)
A new, convenient and efficient AgNO3-catalyzed strategy for the preparation of 2-(benzo[d]azol-2-yl)phenol derivatives in good to excellent yields (63–98%) is described. The reaction proceeds via condensation/intramolecular nucleophilic addition/oxidation process between substituted salicylaldehydes and 2-aminothiophenol, 2-aminophenol or benzene-1,2-diamine under mild reaction conditions. Notably, this reaction utilizes cheap AgNO3 as a readily available and low-cost benign oxidant at low catalyst loadings with excellent functional group tolerance.
Group 4 complexes of salicylbenzoxazole ligands as effective catalysts for the ring-opening polymerization of lactides, epoxides and copolymerization of ε-caprolactone with L-lactide
Pappuru, Sreenath,Chakraborty, Debashis,Vijaya Sundar,Roymuhury, Sagnik K.,Ramkumar, Venkatachalam,Subramanian, Vinodh,Chand, Dillip Kumar
, p. 231 - 247 (2016/09/21)
A series of salicylbenzoxazole pro-ligand 2-(5-X-benzoxazol-2-yl)-6-R1-4-R2-phenol, L1H-L4H were subjected to reaction with titanium, zirconium and hafnium alkoxides. The substituents (R1, R2, X) present in the pro-ligand back bone are (H, H, H) for L1H; (H, H, Cl) for L2H; (Br, Br, H) for L3H; and (Cl, Cl, H) for L4H. The mononuclear Ti complexes, 1a-4a of [M(L)2(OiPr)2] formulation were prepared by combining the pro-ligands L1H-L4H with Ti(OiPr)4 in dry toluene. However, with the addition of H2O (0.5?M equiv.), the controlled hydrolysis of Ti complex 4a in a mixed solvent of THF/toluene produced oxo-bridged dinuclear Ti complex 5a having [M(μ-O)(L)2(OiPr)]2 formulation in good yield (≥75%) using L4H as the pro-ligand. The composition of the mononuclear Zr and Hf complexes of L1H-L4H are found to be quite similar to that of the Ti complexes. Additionally, mononuclear Zr complexes 1b-4b and Hf complexes 1c-4c were prepared. The oxo-bridged dinuclear Zr and Hf complexes 5b and 5c were isolated from the controlled hydrolysis reactions of mononuclear Zr and Hf complexes 4b and 4c. All these complexes were well characterized and crystal structure of six of the fifteen complexes were determined. These complexes were used as initiators for the ring-opening polymerization (ROP) of rac-LA, copolymerization of L-LA with ε-CL and homopolymerization of rac-epoxides. In particular, the dinuclear Zr complex (5b) was found to exhibit extremely high activity in these polymerization studies. Iso-enriched polymers were observed upon using the Zr and Hf complexes of the pro-ligands L3H or L4H as the initiator. DFT studies have been carried out on the ROP of lactides initiated by the Ti, Zr and Hf complexes 1a, 1b and 1c. The results indicated that the activation barrier to reach the transition state using Zr complexes is lower and hence facile as compared to the Ti and Hf complexes.
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.
Application of nano SnO2 as a green and recyclable catalyst for the synthesis of 2-aryl or alkylbenzoxazole derivatives under ambient temperature
Vahdat, Seyed Mohammad,Raz, Shima Ghafouri,Baghery, Saeed
, p. 579 - 585 (2014/07/07)
Application of nano SnO2 as an efficient and benign catalyst has been explored for the synthesis of 2-aryl or alkylbenzoxazole derivatives via condensation reaction of aldehyde with 2-aminophenol. The reactions proceed under heterogeneous and mild conditions in ethanol at room temperature to provide 2-aryl or alkylbenzoxazoles in high yields.
Phenylboronic acid catalyzed-cyanide promoted, one-pot synthesis of 2-(2-hydroxyphenyl)benzoxazole derivatives
Lopez-Ruiz, Heraclio,Briseno-Ortega, Horacio,Rojas-Lima, Susana,Santillan, Rosa,Farfan, Norberto
supporting information; experimental part, p. 4308 - 4312 (2011/08/22)
A novel, one-pot, phenylboronic acid catalyzed, cyanide promoted synthesis of 2-(2-hydroxyphenyl)benzoxazoles from salicylaldehydes and o-aminophenols is described. The synthesis is characterized by mild conditions, short reaction times, and simple workup of crystalline, high purity products.
An efficient potassium cyanide-promoted synthesis of 2-arylbenzoxazoles from [4.3.0]boron heterobicycles
López-Ruiz, Heraclio,Brise?o-Ortega, Horacio,Rojas-Lima, Susana,Santillán, Rosa,Farfán, Norberto
experimental part, p. 2633 - 2635 (2010/06/16)
The 2-arylbenzoxazoles 3a-f were produced in moderate to excellent yields merely by stirring a potassium cyanide (3 equiv)-containing methanol solution of the borobicyclic compounds 1a-f at room temperature. These compounds were fully characterized spectroscopically [IR, 1H, and 13C NMR and X-ray analysis (3a)] and by elemental analysis. Crown Copyright
