7005-72-3Relevant articles and documents
Copper nanoparticle anchored biguanidine-modified Zr-UiO-66 MOFs: a competent heterogeneous and reusable nanocatalyst in Buchwald-Hartwig and Ullmann type coupling reactions
Veisi, Hojat,Neyestani, Narges,Pirhayati, Mozhgan,Ahany Kamangar, Sheida,Lotfi, Shahram,Tamoradi, Taiebeh,Karmakar, Bikash
, p. 22278 - 22286 (2021/07/02)
We have designed a functionalized metal-organic framework (MOF) of UiO topology as a support, with an extremely high surface area, adjustable pore sizes and stable crystalline coordination polymeric structure and implanted copper (Cu) nanoparticles thereon. The core three dimensional Zr-derived MOF (UiO-66-NH2) was modified with a biguanidine moiety following a covalent post-functionalization approach. The morphological and physicochemical features of the material were determined using analytical methods such as FT-IR, SEM, TEM, EDX, atomic mapping, XRD and ICP-OES. The SEM and XRD results justified the unaffected morphology of Zr-MOF after structural modifications. The as-synthesized UiO-66-biguanidine/Cu nanocomposite was catalytically explored in the aryl and heteroaryl Buchwald-Hartwig C-N and Ullmann type C-O cross coupling reactions with excellent yields. A library of biaryl amine and biaryl ethers was synthesized over the catalyst under mild and green conditions. Furthermore, the catalyst was isolated by centrifugation and recycled 11 times with no significant copper leaching or change in its activity.
Synergistic effect of copper nanocrystals-nanoparticles incorporated in a porous organic polymer for the Ullmann C-O coupling r–eaction
Gorginpour, Forough,Zali-Boeini, Hassan
, (2021/02/22)
A quinoxaline-based porous organic polymer (Q-POP) as a mesoporous organic copolymer was developed as a new platform for the immobilization of CuNPs and copper nanocrystals. The prepared materials were characterized by FT-IR, XRD, N2 adsorption-desorption isotherms, ICP, TGA, SEM, HR-TEM, EDX, and single-crystal X-ray crystallography. The obtained catalyst presented extraordinary catalytic activity towards Ullmann C–O coupling reactions with high surface area, hierarchical porosity, and excellent thermal and chemical stability. Due to its high porosity, and synergistic effect of copper nanocrystals incorporated in the polymer composite, the as-synthesized catalyst was successfully utilized for the Ullmann C–O coupling reaction of phenols and different aryl halides to prepare various diaryl ether derivatives. All types of aryl halides (except aryl fluorides) were screened in the Ullmann C–O coupling reaction with phenols to produce diaryl ethers in good to excellent yields (70–97 %), and it was found that aryl iodides have the best results. Besides, due to the strong interactions between CuNPs, N, and O-atoms of quinoxaline moiety existing in the polymeric framework, the copper leaching from the support was not observed. Furthermore, the catalyst was recycled and reused for five consecutive runs without significant activity loss.
Trimethoxyphenyl (TMP) as a Useful Auxiliary for in situ Formation and Reaction of Aryl(TMP)iodonium Salts: Synthesis of Diaryl Ethers
Gallagher, Rory T.,Basu, Souradeep,Stuart, David R.
, p. 320 - 325 (2019/12/11)
Herein, we describe a synthetic approach for arylation that exploits the in situ formation and reaction of an unsymmetrical diaryliodonium salt. In this way, aryl iodides are used as reagents in a metal-free reaction with phenols, and a trimethoxyphenyl (TMP) group is used as a “dummy” group to facilitate transfer of a wide range of aryl moieties. The scope of aryl electrophiles and phenol nucleophiles is broad (>30 examples) and the yields are high (52–95%, 80% avg.). One-pot coupling reactions avoid the synthesis of diaryliodonium salts and provide opportunities for sequential reactions and novel chemoselectivity. (Figure presented.).