2367-02-4Relevant articles and documents
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.
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.
Diaryl Ether Formation Merging Photoredox and Nickel Catalysis
Liu, Le,Nevado, Cristina
supporting information, p. 2188 - 2193 (2021/05/04)
Photoredox and Ni catalysis are combined to produce diaryl ethers under mild conditions. A broad range of aryl halides and phenol derivatives are cross-coupled in the presence of a readily available organic photocatalyst and NiBr2(dtbpy). Symmetrical diaryl ethers have also been directly obtained from aryl bromides in the presence of water. Mechanistic investigations support the involvement of Ni(0) species at the outset of the reaction and a Ni(II)/Ni(III)-photocatalyzed single electron transfer process preceding the productive C(sp2)-OAr reductive elimination.
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.
Nickel-Mediated Trifluoromethylation of Phenol Derivatives by Aryl C?O Bond Activation
Hu, Wei-Qiang,Pan, Shen,Qing, Feng-Ling,Vicic, David A.,Xu, Xiu-Hua
, p. 16076 - 16082 (2020/07/04)
The increasing pharmaceutical importance of trifluoromethylarenes has stimulated the development of more efficient trifluoromethylation reactions. Tremendous efforts have focused on copper- and palladium-mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel-mediated trifluoromethylation of phenol derivatives with readily available trimethyl(trifluoromethyl)silane (TMSCF3). The strategy relies on PMe3-promoted oxidative addition and transmetalation, and CCl3CN-induced reductive elimination. The broad utility of this transformation has been demonstrated through the direct incorporation of trifluoromethyl into aromatic and heteroaromatic systems, including biorelevant compounds.
Isolation of OH-bridged Ag(i)/Cu(iii) and ion-pair Cu(i)/Cu(iii) trifluoromethyl complexes with monophosphines
Xiao, Chang,Zhang, Song-Lin
supporting information, p. 848 - 853 (2019/01/21)
Cu(iii)-CF3 complexes are important intermediates of both synthetic and mechanistic interest. This study describes the isolation, and spectroscopic and X-ray crystallographic characterization of CuIII-CF3 complexes 2-4 with typical monophosphine ligands PPh3 and Buchwald-type biarylmonophosphines. Distinct from the ion-pair [P2Cu(i)]+[Cu(iii)(CF3)4]? structures of 2 and 4 (P: PPh3 or SPhos), complex 3 exhibits a novel OH-bridged Ag(i)-Cu(iii) dinuclear structure with XPhos-coordinated linear Ag(i) and square planar Cu(iii) components. This is the first heterobimetallic Cu(iii)-CF3 complex confirmed by both solution-phase NMR spectroscopy and solid state X-ray crystal structure analysis. Complex 3 is found to have the LUMO orbital of major σ*(Cu-CF3) nature and electrophilic CF3 ligands. Accordingly, complex 3 is able to trifluoromethylate 2 equivalents of aryl boronic acids in up to quantitative yields, regardless of the inert or oxidative conditions. In contrast, the ion-pair complexes 2 and 4 show low reactivity. This study enriches the coordination and reactivity chemistry of Cu(iii)-CF3 compounds and shows the feasibility of modulation of structures and reactivity by ligand design, which may inspire future efforts on Cu(iii)-CF3 chemistry.
Palladium-Catalyzed Decarbonylative Trifluoromethylation of Acid Fluorides
Keaveney, Sinead T.,Schoenebeck, Franziska
, p. 4073 - 4077 (2018/03/21)
While acid fluorides can readily be made from widely available or biomass-feedstock-derived carboxylic acids, their use as functional groups in metal-catalyzed cross-coupling reactions is rare. This report presents the first demonstration of Pd-catalyzed
Diverse copper(iii) trifluoromethyl complexes with mono-, bi- and tridentate ligands and their versatile reactivity
Zhang, Song-Lin,Xiao, Chang,Wan, Hai-Xing
supporting information, p. 4779 - 4784 (2018/04/11)
Cu(iii) trifluoromethyl complexes are proposed as essential intermediates for many copper-promoted trifluoromethylation reactions, but remain elusive and scarcely explored. We report herein the isolation and spectroscopic and X-ray crystallographic charac
Highly efficient heterogeneous copper-catalysed O-arylation of phenols by nitroarenes leading to diaryl ethers
Du, Yingying,Yao, Fang,Tuo, Yuxin,Cai, Mingzhong
, p. 725 - 729 (2018/01/08)
The heterogeneous O-arylation of phenols by nitroarenes was achieved in DMF at 100 °C by using an MCM-41-immobilised bidentate nitrogen copper(II) complex [MCM-41-2N-Cu(OAc)2] as catalyst, yielding a variety of unsymmetrical diaryl ethers in good to excellent yields. This heterogeneous copper catalyst can be easily prepared by a simple procedure from commercially readily available and inexpensive reagents, recovered by filtration of the reaction solution and recycled at least seven times without significant loss of activity.
Isolation and characterization of copper(III) trifluoromethyl complexes and reactivity studies of aerobic trifluoromethylation of arylboronic acids
Zhang, Song-Lin,Bie, Wen-Feng
, p. 70902 - 70906 (2016/08/05)
The isolation, characterization and reactivity of transition metal trifluoromethyl complexes are fundamental and challenging topics in trifluoromethylation chemistry. We report herein the synthesis and isolation of two new complexes [(phen)CuI(PPh3)2]+[CuIII(CF3)4]- (2) and (phen)CuIII(CF3)3 (3) as well as a known complex (bpy)CuIII(CF3)3 (4) at room temperature. 2 and 3 have been fully characterized using 1H, 19F, 31P NMR, elemental analyses and X-ray crystallography. Reactivity studies indicate that 2 is unreactive toward arylboronic acids. In contrast, 3 and 4 can react with various aryl and heteroaryl boronic acids to deliver trifluoromethylated arenes in good to quantitative yields under mild conditions. The presence of a fluoride additive in DMF under aerobic conditions is crucial to these reactions. This study provides fundamental information about the structure and reactivity of elusive Cu(iii) trifluoromethyl complexes that have been proposed as relevant reactive intermediates in many trifluoromethylation reactions.
