3402-72-0Relevant 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.
Solvent-free palladium-catalyzed C–O cross-coupling of aryl bromides with phenols
Asachenko, Andrey F.,Bogachev, Vasilii N.,Cherkashchenko, Ilia R.,Lavrov, Konstantin V.,Minaeva, Lidiya I.,Nechaev, Mikhail S.,Rzhevskiy, Sergey A.,Sterligov, Grigorii K.,Topchiy, Maxim A.
, p. 409 - 411 (2021/06/07)
A new solvent-free procedure for C–O cross-coupling between phenols and aryl bromides comprising of Pd2(dba)3/ButBrettPhos catalytic system is efficient for substrates bearing donor or acceptor, as well as bulky substituents.
Oxalohydrazide Ligands for Copper-Catalyzed C?O Coupling Reactions with High Turnover Numbers
Ray, Ritwika,Hartwig, John F.
supporting information, p. 8203 - 8211 (2021/03/08)
Here, we report a class of ligands based on oxalohydrazide cores and N-amino pyrrole and N-amino indole units that generates long-lived copper catalysts for couplings that form the C?O bonds in biaryl ethers. These Cu-catalyzed coupling of phenols with aryl bromides occurred with turnovers up to 8000, a value which is nearly two orders of magnitude higher than those of prior couplings to form biaryl ethers and nearly an order of magnitude higher than those of any prior copper-catalyzed coupling of aryl bromides and chlorides. This ligand also led to copper systems that catalyze the coupling of aryl chlorides with phenols and the coupling of aryl bromides and iodides with primary benzylic and aliphatic alcohols. A wide variety of functional groups including nitriles, halides, ethers, ketones, amines, esters, amides, vinylarenes, alcohols and boronic acid esters were tolerated, and reactions occurred with aryl bromides in pharmaceutically related structures.
Benzylic C?H Functionalisation by [Et3SiH+KOtBu] leads to Radical Rearrangements in o-tolyl Aryl Ethers, Amines and Sulfides
Arokianathar, Jude N.,Kolodziejczak, Krystian,Bugden, Frances E.,Clark, Kenneth F.,Tuttle, Tell,Murphy, John A.
supporting information, p. 2260 - 2267 (2020/05/06)
Reaction of Et3SiH+KOtBu with diaryl ethers, sulfides and amines that feature an ortho alkyl group leads to rearrangement products. The rearrangements arise from formation of benzyl radicals, likely formed through hydrogen atom abstraction by triethylsilyl radicals. The rearrangements involve cyclisation of the benzyl radical onto the partner arene, which, from computation, is the rate determining step. In the case of diaryl ethers, Truce-Smiles rearrangements arise from radical cyclisations to form 5-membered rings, but for diarylamines, cyclisations to form dihydroacridines are observed. (Figure presented.).
N-Picolinamides as ligands in Ullman type C–O coupling reactions
Damkaci, Fehmi,Sigindere, Cihad,Sobiech, Thomas,Vik, Erik,Malone, Joshua
supporting information, p. 3559 - 3564 (2017/10/05)
Copper-catalyzed modified Ullmann coupling reactions creating C–O bonds, including diaryl ethers or phenols, are vital to organic synthesis. Synthesized N-phenyl-2-pyridinecarboxamide and its derivatives were used as ligands in conjunction with catalytic copper sources in the formation of various diaryl ethers and phenols. Various aryl and heteroaryl halides with electron donating and withdrawing groups were reacted with various phenols under mild reaction conditions providing moderate to excellent yields.
Copper-Catalyzed Diaryl Ether Formation from (Hetero)aryl Halides at Low Catalytic Loadings
Zhai, Yuntong,Chen, Xiaofei,Zhou, Wei,Fan, Mengyang,Lai, Yisheng,Ma, Dawei
, p. 4964 - 4969 (2017/05/12)
Diaryl formation is achieved by coupling phenols and (hetero)aryl halides under the catalysis of CuI/N,N′-bis(2-phenylphenyl) oxalamide (BPPO) or CuI/N-(2-phenylphenyl)-N′-benzyl oxalamide (PPBO) at 90 °C using DMF or MeCN as the solvent. Only 0.2-2 mol % CuI and ligand are required for complete conversion, which represents the lowest catalytic loadings for a general Cu/ligand-catalyzed diaryl ether formation.
Competing Pathways in O-Arylations with Diaryliodonium Salts: Mechanistic Insights
Stridfeldt, Elin,Lindstedt, Erik,Reitti, Marcus,Blid, Jan,Norrby, Per-Ola,Olofsson, Berit
, p. 13249 - 13258 (2017/09/12)
A mechanistic study of arylations of aliphatic alcohols and hydroxide with diaryliodonium salts, to give alkyl aryl ethers and diaryl ethers, has been performed using experimental techniques and DFT calculations. Aryne intermediates have been trapped, and additives to avoid by-product formation originating from arynes have been found. An alcohol oxidation pathway was observed in parallel to arylation; this is suggested to proceed by an intramolecular mechanism. Product formation pathways via ligand coupling and arynes have been compared, and 4-coordinated transition states were found to be favored in reactions with alcohols. Furthermore, a novel, direct nucleophilic substitution pathway has been identified in reactions with electron-deficient diaryliodonium salts.
CuI/oxalamide catalyzed couplings of (hetero)aryl chlorides and phenols for diaryl ether formation
Fan, Mengyang,Zhou, Wei,Jiang, Yongwen,Ma, Dawei
supporting information, p. 6211 - 6215 (2016/05/24)
Couplings between (hetero)aryl chlorides and phenols can be effectively promoted by CuI in combination with an N-aryl-N′-alkyl-substituted oxalamide ligand to proceed smoothly at 120 °C. For this process, N-aryl-N′-alkyl-substituted oxalamides are more effective ligands than bis(N-aryl)-substituted oxalamides. A wide range of electron-rich and electron-poor aryl and heteroaryl chlorides gave the corresponding coupling products in good yields. Satisfactory conversions were achieved with electron-rich phenols as well as a limited range of electron-poor phenols. Catalyst and ligand loadings as low as 1.5 mol % are sufficient for the scaled-up variants of some of these reactions. Aryl and alkyl: N-Aryl-N′-alkyl-substituted oxalamide ligands promote the CuI catalyzed coupling of (hetero)aryl chlorides and phenols at 120 °C more effectively than bis(N-aryl)-substituted oxalamides. A wide range of electron-rich and electron-poor aryl and heteroaryl chlorides were converted into the corresponding coupling products in good yields.
Copper-catalyzed Ullmann-type synthesis of diaryl ethers assisted by salicylaldimine ligands
Qian, Cun-Wei,Lv, Wen-Lin,Zong, Qian-Shou,Wang, Mao-Yuan,Fang, Dong
, p. 337 - 340 (2014/02/14)
A series of salicylaldimine ligands were designed to promote the copper-catalyzed Ullmann cross-coupling reaction. After a screening process, 2-((2-isopropylphenylimino)methyl)phenol was found to serve as a good supporting ligand for this reaction. Employing this Schiff-base ligand as a new supporting ligand, the copper-catalyzed coupling reactions of aryl bromides and aryl iodides with various phenols successfully proceeded in good yields under mild conditions. Various diaryl ethers were obtained with excellent yields in dioxane in the presence of K3PO4 and a catalytic amount of copper(I) salt.
