58636-31-0Relevant academic research and scientific papers
Synthesis and properties of hyperbranched polyimides derived from novel triamine with prolonged chain segments
Shen, Jie,Zhang, Ying,Chen, Wenqiu,Wang, Wenhao,Xu, Zushun,Yeung, Kelvin W. K.,Yi, Changfeng
, p. 2425 - 2437 (2013)
Novel pyridine-containing hyperbranched polyimides (HBPIs) were synthesized by using a new triamine 2,4,6-tris[3-(4-aminophenoxy)phenyl]pyridine with prolonged chain segments, ether linkage and meta-linked units as a BB′2-like monomer, various commercial aromatic dianhydrides as A2 monomers. Most of the obtained HBPIs were readily soluble in common organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, m-Cresol, and so forth. Meanwhile, they also had good thermal stability with the glass transition temperatures (Tgs) all above 210 °C, the temperature at 10% weight loss of 537.1-574.4 °C in nitrogen atmosphere. Strong and flexible HBPI films were obtained, which had good mechanical properties with tensile strengths of 83.3-95.8 MPa, tensile modulus of 1.82-2.43 GPa and elongations at break of 4.84-6.98%.
Picolinamides as effective ligands for copper-catalysed aryl ether formation: Structure-activity relationships, substrate scope and mechanistic investigations
Sambiagio, Carlo,Munday, Rachel H.,Marsden, Stephen P.,Blacker, A. John,McGowan, Patrick C.
supporting information, p. 17606 - 17615 (2015/02/05)
The use of picolinic acid amide derivatives as an effective family of bidentate ligands for copper-catalysed aryl ether synthesis is reported. A fluorine-substituted ligand gave good results in the synthesis of a wide range of aryl ethers. Even bulky phenols, known to be very challenging substrates, were shown to react with aryl iodides with excellent yields using these ligands. At the end of the reaction, the first examples of end-of-life Cu species were isolated and identified as CuII complexes with several of the anionic ligands tested. A preliminary mechanistic investigation is reported that suggests that the substituents on the ligands might have a crucial role in determining the redox properties of the metal centre and, consequently, its efficacy in the coupling process. An understanding of these effects is important for the development of new efficient and tunable ligands for copper-based chemistry.
A homologous enolate Truce-Smiles rearrangement
Mitchell, Lorna H.,Barvian, Nicole C.
, p. 5669 - 5671 (2007/10/03)
During preparation of a series of diphenyl ethers it was observed that displacement of an activated aryl fluoride with ortho-hydroxyacetophenone afforded a product that was C-arylated adjacent to the ketone. Evidence suggested this product was formed by Smiles rearrangement of an O-arylated intermediate.
