2244-88-4Relevant articles and documents
Nucleophilic aromatic substitution of unactivated fluoroarenes enabled by organic photoredox catalysis
Nicewicz, David A.,Pistritto, Vincent A.,Schutzbach-Horton, Megan E.
supporting information, p. 17187 - 17194 (2020/11/02)
Nucleophilic aromatic substitution (SNAr) is a classical reaction with well-known reactivity toward electron-poor fluoroarenes. However, electron-neutral and electron-rich fluoro(hetero)arenes are considerably underrepresented. Herein, we present a method for the nucleophilic defluorination of unactivated fluoroarenes enabled by cation radical-accelerated nucleophilic aromatic substitution. The use of organic photoredox catalysis renders this method operationally simple under mild conditions and is amenable to various nucleophile classes, including azoles, amines, and carboxylic acids. Select fluorinated heterocycles can be functionalized using this method. In addition, the late-stage functionalization of pharmaceuticals is also presented. Computational studies demonstrate that the site selectivity of the reaction is dictated by arene electronics.
The Catalytic Properties of a Copper-Based Nanoscale Coordination Polymer Fabricated by a Solvent-Etching Top-Down Route
Cao, Xiaowei,Fang, Zhenlan,Huang, Wei,Ju, Qiang
supporting information, p. 4803 - 4807 (2017/11/14)
Manipulating particle size is a powerful means of creating unprecedented applications in both inorganic and organic materials. Coordination polymers, which are emerging as a type of organic–inorganic hybrid materials, have attracted thriving interest in a variety of applications, but nanoscale coordination polymers have scarcely been touched. In this work, the pure-phase {Cu6[1,4-bis(imidazol-1-yl)butane]3I6}∞ coordination polymer with different sizes and morphologies was synthesized for the first time through a facile top-down route assisted by solvent etching. The size and morphology could be adjusted simply by varying the participating etching solvents. Our mechanistic investigations suggest that the bulk coordination polymer as a precursor in the etching solvents may experience a process of dispersion, dissolution, and recrystallization to generate the nanoscale counterpart. High catalytic activity of the nanoscale coordination polymer was observed in the N-arylation of imidazole aryl halides, and this was attributed to a high surface area and a low coordination number of unsaturated coordination sites. This simple and rapid preparation, requiring neither specialized equipment nor harsh conditions, suggests a wealth of potential for reducing the size of coordination polymers to comply with various practical applications.
Highly active recyclable heterogeneous Pd/ZnO nanoparticle catalyst: Sustainable developments for the C-O and C-N bond cross-coupling reactions of aryl halides under ligand-free conditions
Hosseini-Sarvari, Mona,Razmi, Zahra
, p. 44105 - 44116 (2014/12/10)
Efficient Pd supported on ZnO nanoparticles for the ligand-free O-arylation and N-arylation of phenols and various N-H heterocycles with aryl chlorides, bromides, and iodides were readily synthesized and characterized. The amount of palladium on ZnO is 9.84 wt% (0.005 g of the catalyst contains 462 × 10-8 mol% of Pd) which was determined by ICP analysis. This nano sized Pd/ZnO with an average particle size of 20-25 nm and specific surface area 40.61 m2 g-1 was used as a new reusable heterogeneous catalyst for the formation of C-O and C-N bonds in organic synthesis. This protocol gives the arylated product in satisfactory yields without any N2 or Ar flow. The catalyst can be recovered and recycled several times without marked loss of activity.
