3096-81-9Relevant articles and documents
Ligand-free copper-catalyzed coupling of phenols with nitroarenes by using a metal-organic framework as a robust and recoverable catalyst
Phan, Nam T. S.,Nguyen, Tung T.,Nguyen, Vu T.,Nguyen, Khoa D.
, p. 2374 - 2381 (2013)
A highly porous metal-organic framework Cu2(BDC)2(DABCO) (H2BDC=1,4-benzenedicarboxylic acid, DABCO=1,4-diazabicyclo[2.2.2]octane) was synthesized and used as an efficient recyclable heterogeneous catalyst for the coupling reaction of phenols with nitroarenes to form diaryl ethers without using a ligand. Physical characterization of the MOF was obtained by using XRD, SEM, TEM, thermogravimetric analysis (TGA), FTIR spectroscopy, atomic absorption spectrophotometry (AAS), H2 temperature-programmed reduction (H2-TPR), and N2 physisorption measurements. The Cu2(BDC)2(DABCO)-catalyzed coupling reaction offers several advantages compared to the conventional Ullmann reaction for the synthesis of unsymmetrical diaryl ethers. To the best of our knowledge, the ligand-free Cu-catalyzed O-arylation reaction of phenols with nitroarenes that uses a heterogeneous catalyst has not been mentioned previously in the literature.
Palladium-catalyzed formation of diaryl ethers from aryl bromides. Electron poor phosphines enhance reaction yields
Mann, Grace,Hartwig, John F.
, p. 8005 - 8008 (1997)
Aryl bromides were converted to diaryl ethers with sodium aryl oxides in the presence of catalytic amounts of Pd(DBA)2 and DPPF. Isolated yields of over 90% were achieved in reactions with electron deficient aryl bromides and electron rich sodium aryl oxides. Electron poor DPPF derivatives led to increased reaction yields.
Nickel-Catalyzed Etherification of Phenols and Aryl Halides through Visible-Light-Induced Energy Transfer
Zhu, Da-Liang,Jiang, Shan,Wu, Qi,Wang, Hao,Li, Hai-Yan,Li, Hong-Xi
supporting information, p. 8327 - 8332 (2021/10/25)
Notwithstanding some progress in nickel-catalyzed etherification of alkanols and arylhalides, the ability of such a Ni-catalyzed transformation employing phenols to diaryl ethers is unsuccessful due to phenolates with much lower reduction potentials, which suppress the oxidation of nickel(II) intermediates into requisite Ni(III) species. We herein report visible-light-initiated, nickel-catalyzed O-arylation of phenols with arylhalides using t-BuNH(i-Pr) as the base and thioxanthen-9-one as the photosensitizer under visible light. This photocoupling exhibits a broad substrate scope.
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.