61430-75-9Relevant articles and documents
From agriculture residue to catalyst support; A green and sustainable cellulose-based dip catalyst for C–C coupling and direct arylation
Kandathil, Vishal,Kempasiddaiah, Manjunatha,B. S., Sasidhar,Patil, Siddappa A.
, (2019/07/31)
The core characteristics of a perfect catalyst include good activity, simple design, excellent stability, easy recovery from reaction mixture, recyclability, and have the provision for easy scale up. The ease in synthesis, recyclability and scale up makes the dip catalyst a major contender in this regard which possess most of the aforementioned characteristics. In this work, we report a dip catalyst made of cellulose, isolated from agriculture residue (sugarcane bagasse), in which biogenically synthesized palladium nanoparticles were dispersed. The prepared dip catalyst was characterized by FESEM, EDS, XRD, ATR-IR, TGA, TEM, XPS and ICP-OES analysis. Also, the activity of the dip catalyst was studied in the Suzuki-Miyaura cross-coupling reaction and was found to give excellent conversion with 15 recycles. Further, the activity of dip catalyst in C5-arylation of 2-substituted thiophenes was evaluated for which promising yields were obtained.
Microwave-assisted, ligand-free, direct C-H arylation of thiophenes in biomass-derived γ-valerolactone
Tabasso, Silvia,Calcio Gaudino, Emanuela,Rinaldi, Laura,Ledoux, Audrey,Larini, Paolo,Cravotto, Giancarlo
supporting information, p. 9210 - 9215 (2017/08/29)
The Pd-catalyzed C-H arylation of heterocycles with aryl halides is a straightforward and more environmentally-friendly route to the synthesis of well-defined, pi-conjugated polymers for challenging applications in electronic devices. Although this type of transformation is more atom efficient than cross-couplings, it still poses environmental issues in the form of reaction media and the use of phosphine ligands. A procedure for the C-H arylation of thiophenes, with a substantially improved environmental impact, and a promising application of this protocol to the synthesis of regioregular polythiophenes are reported in this work. γ-Valerolactone (GVL), a non-toxic biomass-derived solvent, has been used in this phosphine-free microwave-assisted process and replaces commonly used dipolar aprotic media. Activated aryl bromides gave arylthiophenes in good yields, while iodides were used and pivalic acid was added when electron-withdrawing groups were present. The reaction was also extended to C-H (hetero)arylation polycondensation and a high molecular weight poly(3-hexyl)thiophene was obtained, using low Pd loading, in high yields and good regioregularity in short reaction times. Computational studies have shed light on GVL's role as a ligand in the catalytic system.
Synthesis of heterocycles on the basis of arylation products of unsaturated compounds. 19. Arylation of 2-acetylthio- phene and the synthesis of 2-(5-aryl-2-thien- yl)-4-quinolinecarboxylic acids
Matiychuk,Obushak,Lytvyn,Horak, Yu. I.
experimental part, p. 50 - 55 (2010/08/05)
The reaction of 2-acetylthiophene with acetylthiophene with arenediazonium chlorides in the presence of cupric chloride as catalyst gives 2-acetyl-5-arylthiophenes. These products react with 5-chloro- and 5-bromoisatins to give 6-chloro- and 6-bromo-subst
