88280-58-4Relevant articles and documents
Revealing Topological Influence of Phenylenediamine Unit on Physicochemical Properties of Donor-Acceptor-Donor-Acceptor Thermally Activated Delayed Fluorescent Macrocycles
Data, Przemyslaw,Izumi, Saika,Minakata, Satoshi,Nyga, Aleksandra,Takeda, Youhei,Tohnai, Norimitsu,de Silva, Piotr
, p. 4098 - 4103 (2020)
A new thermally activated delayed fluorescence (TADF)-displaying macrocyclic compound m-1 comprising of two electron-donors (N,N’-diphenyl-m-phenylenediamine) and two electron-acceptors (dibenzo[a,j]phenazine) has been synthesized. The macrocycle developed herein is regarded as a regioisomer of the previously reported TADF macrocycle p-1, which has two N,N’-diphenyl-p-phenylenediamines as the donors. To understand the influence of the topology of the phenylenediamine donors on physicochemical properties of TADF-active macrocycles, herein the molecular structure in the single crystals, photophysical properties, electrochemical behavior, and TADF properties of m-1 have been investigated compared with those of p-1. The substitution of p-phenylene donor with m-phenylene donor led to distinct positive solvatoluminochromism over the full visible-color range, unique oxidative electropolymerization, and slightly lower contribution of TADF, due to the lower CT character in the excited states.
Transition Metal-Free Synthesis of meta-Bromo- and meta-Trifluoromethylanilines from Cyclopentanones by a Cascade Reaction
Bunch, Lennart,Cetin, Adnan,Staudt, Markus
supporting information, (2022/02/10)
Anilines are key constituents in biologically active compounds and often obtained from transition metal-catalyzed coupling of an aryl halide with an amine. In this work, we report a transition metal-free method for the synthesis of meta-bromo- and meta-trifluoromethylanilines starting from 3-tribromomethylcyclopentanone or 3-(2-bromo-2-chloro-1,1,1-trifluoroethyl)cyclopentanone, respectively. The scope of the transformation is shown by application of primary, secondary and aromatic amines. The reaction proceeds in acceptable to high yields (20–81 %), and allows for the synthesis of anilines with substitution patterns otherwise difficult to access.
Reductive C?N Coupling of Nitroarenes: Heterogenization of MoO3 Catalyst by Confinement in Silica
Yang, Fu,Dong, Xuexue,Shen, Yang,Liu, Mengting,Zhou, Hu,Wang, Xuyu,Li, Lulu,Yuan, Aihua,Song, Heng
, p. 3413 - 3421 (2021/07/31)
The construction of C?N bonds with nitroaromatics and boronic acids using highly efficient and recyclable catalysts remains a challenge. In this study, nanoporous MoO3 confined in silica serves as an efficient heterogeneous catalyst for C?N cross-coupling of nitroaromatics with aryl or alkyl boronic acids to deliver N-arylamines and with desirable multiple reusability. Experimental results suggest that silica not only heterogenizes the Mo species in the confined mesoporous microenvironment but also significantly reduces the reaction induction period and regulates the chemical efficiency of the targeted product. The well-shaped MoO3@m?SiO2 catalyst exhibits improved catalytic performance both in yield and turnover number, in contrast with homogeneous Mo catalysts, commercial Pd/C, or MoO3 nanoparticles. This approach offers a new avenue for the heterogeneous catalytic synthesis of valuable bioactive molecules.
Mediator-Enabled Electrocatalysis with Ligandless Copper for Anaerobic Chan-Lam Coupling Reactions
Walker, Benjamin R.,Manabe, Shuhei,Brusoe, Andrew T.,Sevov, Christo S.
supporting information, p. 6257 - 6265 (2021/05/07)
Simple copper salts serve as catalysts to effect C-X bond-forming reactions in some of the most utilized transformations in synthesis, including the oxidative coupling of aryl boronic acids and amines. However, these Chan-Lam coupling reactions have historically relied on chemical oxidants that limit their applicability beyond small-scale synthesis. Despite the success of replacing strong chemical oxidants with electrochemistry for a variety of metal-catalyzed processes, electrooxidative reactions with ligandless copper catalysts are plagued by slow electron-transfer kinetics, irreversible copper plating, and competitive substrate oxidation. Herein, we report the implementation of substoichiometric quantities of redox mediators to address limitations to Cu-catalyzed electrosynthesis. Mechanistic studies reveal that mediators serve multiple roles by (i) rapidly oxidizing low-valent Cu intermediates, (ii) stripping Cu metal from the cathode to regenerate the catalyst and reveal the active Pt surface for proton reduction, and (iii) providing anodic overcharge protection to prevent substrate oxidation. This strategy is applied to Chan-Lam coupling of aryl-, heteroaryl-, and alkylamines with arylboronic acids in the absence of chemical oxidants. Couplings under these electrochemical conditions occur with higher yields and shorter reaction times than conventional reactions in air and provide complementary substrate reactivity.
Copper-catalyzed, ceric ammonium nitrate mediated N-arylation of amines
Gonela, Uma Maheshwar,Ablordeppey, Seth Y.
supporting information, p. 2861 - 2864 (2019/02/17)
Cu-Catalyzed, ligand- and base-free cross-coupling of aryl boronic acids with primary and secondary amines has been reported. This ‘Chan-Evans-Lam' reaction has revealed that at room temperature, with a catalytic amount of copper(ii) acetate and ceric ammonium nitrate (CAN) as an oxidant, N-arylation can result in an effective C-N bond formation. This air stable, practical, robust protocol enables tolerance towards a variety of functional groups on both boronic acid and amine partners.
Copper immobilized at a covalent organic framework: An efficient and recyclable heterogeneous catalyst for the Chan-Lam coupling reaction of aryl boronic acids and amines
Han, Yi,Zhang, Mo,Zhang, Ya-Qing,Zhang, Zhan-Hui
, p. 4891 - 4900 (2018/11/21)
A polyimide covalent organic framework (PI-COF) with high thermal and chemical stabilities has been readily prepared from commercially available and inexpensive reagents and was employed as an effective support for heterogeneous copper. It was demonstrated that the obtained Cu@PI-COF is a highly active heterogeneous catalyst which can effectively promote the Chan-Lam coupling reaction of aryl boronic acids and amines in an open flask without the aid of any base or additive. In addition, the catalyst could be readily recovered from the reaction mixture by simple filtration and reused for at least eight cycles without any observable change in structure and catalytic activity.
Meta - And para -Functionalized Thermally Crosslinkable OLED-Materials through Selective Transition-Metal-Catalyzed Cross-Coupling Reactions
Hempe, Matthias,Schnellb?cher, Lutz,Wiesner, Tobias,Reggelin, Michael
, p. 4489 - 4499 (2017/09/26)
Herein, a synthetic approach using selective transition-metal-catalyzed cross-coupling reactions to thermally crosslinkable OLED materials based on vinyl-functionalized arylamines is reported. In a modular approach, 9,9-dialkyl-2,7-diiodo-9 H -fluorene underwent a selective Ullmann cross-coupling reaction with bromo-substituted-diphenylamines to give 9,9-dialkyl-2,7-bis(bromo-substituted-diphenylamino)-9 H -fluorenes that underwent end-functionalization by the Suzuki-Miyaura reaction using potassium vinyltrifluoroborate to give the corresponding 9,9-dialkyl-2,7-bis(vinyl-substituted-diphenylamino)-9 H -fluorenes. Novel meta -functionalized materials were synthesized, which are difficult to prepare by traditional synthetic pathways. The thermal behavior of the compounds was investigated by DSC measurements, indicating a lower thermal sensitivity of the meta -substituted materials than their para -functionalized analogues.
O-iodoxybenzoic acid mediated N-arylation of aromatic amines by using arylhydrazines as the arylating counterpart
Jadhav, Ravindra R.,Huddar, Sameerana N.,Akamanchi, Krishnacharya G.
supporting information, p. 6779 - 6783 (2013/11/06)
Through free-radical trapping experiments we have established, for the first time, the combination of arylhydrazines with o-iodoxybenzoic acid (IBX) for the generation of aryl free radicals. On the basis of this finding, a method was developed for the N-arylation of aromatic amines under mild conditions (base-free, -5 °C) by using arylhydrazines as the arylating counterpart and arylamines. The scope of this method was demonstrated by using a number of arylhydrazines and arylamines, which gave the N-arylated amines in good yields. Through free-radical trapping experiments, the present work describes the combination of arylhydrazines with o-iodoxybenzoic acid (IBX) for the generation aryl free radicals. This finding is exploited in the development of a mild method for the N-arylation of arylamines by using arylhydrazines as the arylating agents. The scope of this method is demonstrated through a number of examples. Copyright
Direct amination of phenols under metal-free conditions
Yu, Jianzhong,Wang, Yongtao,Zhang, Peizhi,Wu, Jun
supporting information, p. 1448 - 1454 (2013/07/26)
Herein, we disclose the metal-free synthesis of arylamines via the direct amination of phenols using aminating reagents. This reaction procedure uses easy accessible aminating reagents and provides a versatile synthetic route to a broad range of arylamines with various functionalities in good to excellent yield. By using a two-step route of amination and oxidative coupling reaction, we synthesized three naturally occurring carbazole alkaloids: murrayafoline A, mukonine, and clausenine from two commercially available phenols. Georg Thieme Verlag Stuttgart · New York.
Nickel-catalyzed synthesis of diarylamines via oxidatively induced C-N bond formation at room temperature
Ilies, Laurean,Matsubara, Tatsuaki,Nakamura, Eiichi
supporting information, p. 5570 - 5573,4 (2012/12/12)
A nickel-catalyzed oxidative coupling of zinc amides with organomagnesium compounds selectively produces diarylamines under mild reaction conditions, with tolerance for chloride, bromide, hydroxyl, ester, and ketone groups. A diamine is bis-monoarylated. A bromoaniline undergoes N-arylation followed by Kumada-Tamao-Corriu coupling in one pot. The reaction may proceed via oxidatively induced reductive elimination of a nickel species.
