620-88-2Relevant academic research and scientific papers
Synthesis and characterization of nano-cellulose immobilized phenanthroline-copper (I) complex as a recyclable and efficient catalyst for preparation of diaryl ethers, N-aryl amides and N-aryl heterocycles
Aghili, Nora,Hosseinzadeh, Rahman,Mavvaji, Mohammad
, (2022/01/03)
Functionalized nanocellulose was prepared and employed for immobilization of phenanthroline-copper(I) complex to afford cellulose nanofibril grafted heterogeneous copper catalyst [CNF-phen-Cu(I)]. This nanocatalyst was well characterized using FT-IR, NMR, XRD, CHNS, AAS, TGA, EDX and SEM. The activities of the synthesized catalyst were examined in the synthesis of diaryl ethers via C-O cross-coupling of phenols and aryl iodides, as well as, the preparation of N-aryl amides and N-aryl heterocycles through C-N cross-coupling of amides and N-H heterocycle compounds with aryl halides. In this trend, various substrates containing electron-donating and electron-withdrawing groups were exploited to evaluate the generality of this catalytic protocol. Accordingly, the catalyst demonstrated remarkable catalytic efficiency for both C-N and C-O cross-coupling reactions, thereby resulting in good to excellent yields of the desired products. Furthermore, the recoverability experiments of the catalyst showed that it can be readily retrieved by simple filtration and successfully reused several times with negligible loss of its catalytic activity.
Suzuki?Miyaura coupling and O?arylation reactions catalysed by palladium(II) complexes of bulky ligands bearing naphthalene core, Schiff base functionality and biarylphosphine moiety
Arora, Aayushi,Kaushal, Jolly,Kumar, Arun,Nautiyal, Divyanshu,Oswal, Preeti,Singh, Siddhant
, (2022/01/19)
Schiff bases L1 [i.e., 2-(diphenylphosphino)-N-(naphthalen-1-ylmethylene)ethanamine], L2 [i.e., 2- (diphenylphosphino)-N-(naphthalen-2-ylmethylene)ethanamine], L3 [i.e., 2-(1-(2-(diphenylphosphino)ethylim- ino)ethyl)naphthalen-1-ol] and L4 [i.e., 2-((2-(diphenylphosphino)ethylimino)methyl)naphthalen-1-ol] have been synthesized using a straightforward methodology which involves a condensation reaction between H2N?CH2?CH2?PPh2 and appropriate carbonyl compound. Due to the presence of diphenylphosphine (?PPh2) moiety and >C = N? functionality, these compounds behave as ligands and undergo complexation reaction with palladium on treatment with Na2PdCl4 to yield the palladium(II) complexes (1–4). Ligands as well as complexes have been characterized using standard NMR spectroscopic techniques. ESI?MS and single crystal X?ray diffraction studies corroborate the structures of complexes. Crystal structures of complexes 1?3 reveal clearly that the geometry around Pd centre is distorted square planar. Ligands L1 and L2 are coordinated to Pd centre in bidentate (P, N type) mode, however, L3 and L4 act as a tridentate (P,N,O type) ligand and bind with metal in anionic mode. The Pd P and Pd N bond distances in complexes 1?3 are in the ranges 2.204?2.212 ? and 2.023?2.072 ?, respectively. Complex 3 [i.e., PdCl(L3?H)] also has a Pd-O bond, the length of which is found to be 2.009(3) ?. All the complexes have potential for catalysing O-arylation (C-O coupling) of phenol and Suzuki-Miyaura coupling (SMC) reactions. Both bromoarenes and chloroarenes can be used as substrates in Suzuki coupling and converted into biaryl derivatives. For O-arylation reactions of phenol, bromoarenes are used as arylating agents. For catalysis of such reactions (i.e., C-O coupling), high (0.1 mol%) catalyst loading is required. However, Suzuki reactions require low (0.001 mol%) loading of catalysts to occur with bromoarenes and give the products. The high potential of the complexes is also evident from the fact that they also convert different aryl chlorides into the coupled products in Suzuki coupling. 31P{1H} NMR data reveal that the electronic environments of nuclei of phosphorous donors are closely similar in all the four ligands. Similar magnitude of deshielding of the 31P{1H} signals in all the complexes indicate that, while forming the dative bond, the P donor of all the ligands transfer the electron density to the palladium to a similar extent. Hence, the electronic effects created by the ligands through the phosphorous donor are similar in all the complexes. Therefore, it is inferred that variation in their catalytic performance is because of difference in the binding mode of the ligand and/or minor alteration in the architecture of organic ligand. Amongst them, complex 2 shows the highest catalytic activity, and the least active catalyst is complex 3 for C-C coupling reactions. For C-O coupling reactions, the efficiencies of complexes 1 and 2 are slightly higher than those of complexes 3 and 4.
Diarylation of N- and O-nucleophiles through a metal-free cascade reaction
Bulfield, David,Kervefors, Gabriella,Linde, Erika,Olofsson, Berit,Purkait, Nibadita
, p. 850 - 865 (2022/03/14)
The arylation of heteroatom nucleophiles is a central strategy to reach diarylated compounds that are key building blocks in agrochemicals, materials, and pharmaceuticals. Nucleophilic aromatic substitution is a classical tool for such arylations, and recent developments in hypervalent iodine-mediated arylations allow a wider scope of products. Herein, we combine the benefits of these strategies to enable an efficient and transition-metal-free difunctionalization of N- and O-nucleophiles with two structurally different aryl groups and to provide di- and triarylamines and diaryl ethers in one single step (>100 examples). The core of this strategy is the unique reactivity discovered with specifically designed fluorinated diaryliodonium salts, which unveils novel reaction pathways in hypervalent iodine chemistry. The methodology is suitable for diarylation of aliphatic amines, anilines, ammonia, and even water. It tolerates a wide variety of functional and protecting groups, with the retained iodine substituent easily accessible for derivatization of the products.
Ligand- and Counterion-Assisted Phenol O-Arylation with TMP-Iodonium(III) Acetates
Kikushima, Kotaro,Miyamoto, Naoki,Watanabe, Kazuma,Koseki, Daichi,Kita, Yasuyuki,Dohi, Toshifumi
supporting information, p. 1924 - 1928 (2022/03/27)
High reactivity of trimethoxyphenyl (TMP)-iodonium(III) acetate for phenol O-arylation was achieved. It was first determined that the TMP ligand and acetate anion cooperatively enhance the electrophilic reactivity toward phenol oxygen atoms. The proposed method provides access to various diaryl ethers in significantly higher yields than the previously reported techniques. Various functional groups, including aliphatic alcohol, boronic ester, and sterically hindered groups, were tolerated during O-arylation, verifying the applicability of this ligand- and counterion-assisted strategy.
Structural Development of Salicylanilide-Based SPAK Inhibitors as Candidate Antihypertensive Agents
Fujii, Shinya,Kikuchi, Eriko,Suzuyama, Honoka,Watanabe, Yuko,Ishigami-Yuasa, Mari,Masuno, Hiroyuki,Mori, Takayasu,Isobe, Kiyoshi,Uchida, Shinichi,Kagechika, Hiroyuki
supporting information, p. 2817 - 2822 (2021/07/12)
Hypertension is an important target for drug discovery. We have focused on the with-no-lysine kinase (WNK)-oxidative stress-responsive 1 (OSR1) and STE20/SPS1-related proline-alanine-rich protein kinase (SPAK)-NaCl cotransporter (NCC) signal cascade as a potential target, and we previously developed a screening system for inhibitors of WNK-OSR1/SPAK-NCC signaling. Herein we used this system to examine the structure-activity relationship (SAR) of salicylanilide derivatives as SPAK kinase inhibitors. Structural design and development based on our previous hit compound, aryloxybenzanilide derivative 2, and the veterinary anthelmintic closantel (3) led to the discovery of compound 10 a as a potent SPAK inhibitor with reduced toxicity. Compound 10 a decreased the phosphorylation level of NCC in mouse kidney in vivo, and appears to be a promising lead compound for a new class of antihypertensive drugs.
L-Proline N-oxide dihydrazides as an efficient ligand for cross-coupling reactions of aryl iodides and bromides with amines and phenols
Ding, Zhiqiang,Nie, Nan,Chen, Tian,Meng, Lingxin,Wang, Gongshu,Chen, Zhangpei,Hu, Jianshe
supporting information, (2020/12/21)
A novel catalytic system based on L-proline N-oxide/CuI was developed and applied to the cross-coupling reactions of various N- and O- nucleophilic reagents with aryl iodides and bromides. This strategy featured in the employment of an-proline derived dihydrazides N-oxide compound as the superior supporting ligand. By using this protocol, a variety of products, including N-arylimidazoles, N-arylpyrazoles, N-arylpyrroles, N-arylamines, and aryl ethers, were synthesized with up to 99% yield.
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.
Fe-MIL-101 modified by isatin-Schiff-base-Co: a heterogeneous catalyst for C-C, C-O, C-N, and C-P cross coupling reactions
Farrokhi, Alireza,Rouzifar, Majid,Sansano, José Miguel,Sobhani, Sara
, p. 19963 - 19976 (2021/11/12)
A metal-organic framework functionalized with a cobalt-complex is preparedviapost-synthetic modification of Fe-MIL-101-NH2. Initially, Fe-MIL-101-NH2reacted with isatin to produce Fe-MIL-101-isatin-Schiff-base, which can anchor the cobalt by the addition of cobalt acetate. The resulting MOF-Co catalyst is characterized by employing multiple techniques. This new modified MOF acts as a heterogeneous and recyclable catalyst for efficient Ullmann, Buchwald-Hartwig, Hirao, Hiyama and Mizoroki-Heck cross-coupling reactions of several aryl halides/phenylboronic acid/phenyltosylate with phenols, anilines/heterocyclic amines, triethyl phosphite, triethoxyphenylsilane and alkenes and generates the expected coupling products in good to high yields.
Preparation and characterization of Cu based on 5,5'-bistetrazole as a recyclable metal-organic framework and application in synthesis of diaryl ether by the Ullmann coupling reaction
Noorpoor, Zeinab,Tavangar, Saeed
, p. 1651 - 1662 (2021/05/10)
Cu based on 5,5′-bistetrazole ([Cu2BT · 2H2O] n) as a recyclable metal-organic framework (MOF) heterogeneous catalyst was characterized by FT-IR, 13C NMR, XRD, SEM, EDX, BET, BJH, and ICP-AES analysis. The catalytic activity of the catalyst was probed through the Ullmann reaction for synthesis of diaryl ether derivatives from two component reactions of aromatic arylhalides and phenol derivatives in DMSO. Simple procedure, high yields, short reaction time, and environmentally benign methods are advantages of this protocol. The catalyst was readily separated by simple filtration and reusable without significant loss of its catalytic efficiency.
Magnetization of graphene oxide nanosheets using nickel magnetic nanoparticles as a novel support for the fabrication of copper as a practical, selective, and reusable nanocatalyst in C-C and C-O coupling reactions
Hajjami, Maryam,Moradi, Parisa
, p. 25867 - 25879 (2021/08/09)
Catalyst species are an important class of materials in chemistry, industry, medicine, and biotechnology. Moreover, waste recycling is an important process in green chemistry and is economically efficient. Herein, magnetic graphene oxide was synthesized using nickel magnetic nanoparticles and further applied as a novel support for the fabrication of a copper catalyst. The catalytic activity of supported copper on magnetic graphene oxide (Cu-ninhydrin@GO-Ni MNPs) was investigated as a selective, practical, and reusable nanocatalyst in the synthesis of diaryl ethers and biphenyls. Some of the obtained products were identified by NMR spectroscopy. This nanocatalyst has been characterized by atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM), wavelength dispersive X-ray spectroscopy (WDX), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. The results obtained from SEM shown that this catalyst has a nanosheet structure. Also, XRD and FT-IR analysis show that the structure of graphene oxide and nickel magnetic nanoparticles is stable during the modification of the nanoparticles and synthesis of the catalyst. The VSM curve of the catalyst shows that this catalyst can be recovered using an external magnet; therefore, it can be reused several times without a significant loss of its catalytic efficiency. The heterogeneity and stability of this nanocatalyst during organic reactions was confirmed by the hot filtration test and AAS technique.
