4783-86-2Relevant articles and documents
Cu-based nanoalloys in the base-free ullmann heterocyle-aryl ether synthesis
Engels, Volker,Benaskar, Faysal,Patil, Narendra,Rebrov, Evgeny V.,Hessel, Volker,Hulshof, Lumbertus A.,Jefferson, David A.,Vekemans, Jef A. J. M.,Karwal, Saurabh,Schouten, Jaap C.,Wheatley, Andrew E. H.
, p. 644 - 649 (2010)
We report the first liquid-liquid Ullmann etherification process mediated not only by oxidatively stable Cu but also by CuZn and CuSn nanoparticle catalysts in conjunction with microwave heating that also avoids the use of solid and expensive bases. Condi
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.
Selective Functionalization of Aminoheterocycles by a Pyrylium Salt
Moser, Daniel,Duan, Yaya,Wang, Feng,Ma, Yuanhong,O'Neill, Matthew J.,Cornella, Josep
, p. 11035 - 11039 (2018/07/31)
The functionalization of aminoheterocycles by using a pyrylium tetrafluoroborate reagent (Pyry-BF4) is presented. This reagent efficiently condenses with a great variety of heterocyclic amines and primes the C?N bond for nucleophilic aromatic substitution. More than 60 examples for the formation of C?O, C?N, C?S, or C?SO2R bonds are disclosed herein. In contrast to C?N activation through diazotization and polyalkylation, this method is characterized by its mild conditions and impressive functional-group tolerance. In addition to small-molecule derivatization, Pyry-BF4 allows the introduction of functional groups in a late-stage fashion to furnish highly functionalized structures.
Synthesis of copper nanoparticles supported on a microporous covalent triazine polymer: An efficient and reusable catalyst for O-arylation reaction
Puthiaraj, Pillaiyar,Ahn, Wha-Seung
, p. 1701 - 1709 (2016/04/05)
Copper nanoparticles were supported on a microporous covalent triazine polymer prepared by the Friedel-Crafts reaction (Cu@MCTP-1). The resulting material was characterized by powder X-ray diffraction, thermogravimetric analysis, N2 adsorption-desorption isotherms at 77 K, transmission electron microscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectroscopy, and Cu particles with an average size of 3.0 nm and a BET total surface area of ca. 1002 m2 g-1 were obtained. Cu@MCTP-1 was evaluated as a heterogeneous catalyst for the Ullmann coupling of O-arylation over a series of aryl halides and phenols without employing expensive ligands or inert atmosphere, which produced an excellent yield of the corresponding diaryl ethers. The catalyst could be recovered by simple centrifugation and was reusable at least five times with only a slight decrease in catalytic activity.