41018-73-9Relevant articles and documents
Fe-MIL-101 modified by isatin-Schiff-base-Co: a heterogeneous catalyst for C-C, C-O, C-N, and C-P cross coupling reactions
Farrokhi, Alireza,Rouzifar, Majid,Sansano, José Miguel,Sobhani, Sara
, p. 19963 - 19976 (2021/11/12)
A metal-organic framework functionalized with a cobalt-complex is preparedviapost-synthetic modification of Fe-MIL-101-NH2. Initially, Fe-MIL-101-NH2reacted with isatin to produce Fe-MIL-101-isatin-Schiff-base, which can anchor the cobalt by the addition of cobalt acetate. The resulting MOF-Co catalyst is characterized by employing multiple techniques. This new modified MOF acts as a heterogeneous and recyclable catalyst for efficient Ullmann, Buchwald-Hartwig, Hirao, Hiyama and Mizoroki-Heck cross-coupling reactions of several aryl halides/phenylboronic acid/phenyltosylate with phenols, anilines/heterocyclic amines, triethyl phosphite, triethoxyphenylsilane and alkenes and generates the expected coupling products in good to high yields.
Cu-Catalyzed Cross-Coupling of Nitroarenes with Aryl Boronic Acids to Construct Diarylamines
Guan, Xinyu,Zhu, Haoran,Driver, Tom G.
, p. 12417 - 12422 (2021/10/12)
The development and study of a simple copper-catalyzed reaction of nitroarenes with aryl boronic acids to form diarylamines that uses phenyl silane as the stoichiometric terminal reductant is described. This cross-coupling reaction requires as little as 2 mol % of CuX and 4 mol % of diphosphine for success and tolerates a broad range of functional groups on either the nitroarene or the aryl boronic acid to afford the amine in good yield. Mechanistic investigations established that the cross-coupling reaction proceeds via a nitrosoarene intermediate and that copper is required to catalyze both the deoxygenation of the nitroarene to afford the nitrosoarene and C-NAr bond formation of the nitrosoarene with the aryl boronic acid.
Visible-Light- And PPh3-Mediated Direct C-N Coupling of Nitroarenes and Boronic Acids at Ambient Temperature
Manna, Kartic,Ganguly, Tanusree,Baitalik, Sujoy,Jana, Ranjan
supporting information, p. 8634 - 8639 (2021/11/01)
We present here a metal-free, visible-light- and triphenylphosphine-mediated intermolecular, reductive amination between nitroarenes and boronic acids at ambient temperature without any photocatalyst. Mechanistically, a slow reduction of nitroarenes to a nitroso and, finally, a nitrene intermediate occurs that leads to the amination product with concomitant 1,2-aryl/-alkyl migration from a boronate complex. A wide range of nitroarenes underwent C-N coupling with aryl-/alkylboronic acids providing high yields.
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.
Light-Promoted C–N Coupling of Aryl Halides with Nitroarenes
Li, Gang,Yang, Liu,Liu, Jian-Jun,Zhang, Wei,Cao, Rui,Wang, Chao,Zhang, Zunting,Xiao, Jianliang,Xue, Dong
supporting information, p. 5230 - 5234 (2021/02/05)
A photochemical C–N coupling of aryl halides with nitroarenes is demonstrated for the first time. Catalyzed by a NiII complex in the absence of any external photosensitizer, readily available nitroarenes undergo coupling with a variety of aryl halides, providing a step-economic extension to the widely used Buchwald–Hartwig C–N coupling reaction. The method tolerates coupling partners with steric-congestion and functional groups sensitive to bases and nucleophiles. Mechanistic studies suggest that the reaction proceeds via the addition of an aryl radical, generated from a NiI/NiIII cycle, to a nitrosoarene intermediate.
Copper complexes of 1,4-diazabutadiene ligands: Tuning of metal oxidation state and, application in catalytic C-C and C-N bond formation
Mukherjee, Aparajita,Basu, Semanti,Bhattacharya, Samaresh
, (2019/11/11)
Reaction of 1,4-diazabutadiene (p-RC6H4N = C(H)(H)C = NC6H4R-p; R = OCH3, CH3, H and Cl; abbreviated as L-R) with CuCl2·2H2O in methanol at ambient temperature (25 °C) affords a group of doubly chloro-bridged dicopper complexes of type [{CuI(L-R)Cl}2], designated as 1-R. Similar reaction carried out in acetonitrile furnishes a family of doubly chloro-bridged dicopper complexes of type [{CuII(L-R)Cl2}2], designated as 2-R. Molecular structures of 1-OCH3 and 2-OCH3 have been determined by X-ray crystallography. While copper(I) is having a nearly tetrahedral N2Cl2 coordination sphere in 1-OCH3, the N2Cl3 coordination sphere around copper(II) is distorted square pyramidal in nature in 2-OCH3. Isolated 2-R complexes, on dissolution in methanol, are found to undergo facile reduction of the metal center to generate the corresponding 1-R complexes. The 1-R and 2-R complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the 1-R and 2-R complexes shows both metal-centered and ligand centered redox responses. The 1-R complexes are found to efficiently catalyze C-N cross-coupling reactions between arylboronic acids and aryl amines; while the 2-R complexes display notable catalytic efficiency for nitroaldol reactions.
Electrochemically Enabled Chan-Lam Couplings of Aryl Boronic Acids and Anilines
Wexler, Ryan P.,Nuhant, Philippe,Senter, Timothy J.,Gale-Day, Zachary J.
supporting information, p. 4540 - 4543 (2019/06/27)
The Chan-Lam reaction remains a highly utilized transformation for C-N bond formation. However, anilines remain problematic substrates due to their lower nucleophilicity. To address this problem, we developed an electrochemically mediated Chan-Lam coupling of aryl boronic acids and amines utilizing a dual copper anode/cathode system. The mild conditions identified have enabled the preparation of a wide range of functionalized biarylanilines in good yields and chemoselectivities.
An Effective Heterogeneous Copper Catalyst System for C-N Coupling and Its Application in the Preparation of 2-Methyl-4-methoxydiphenylamine (MMDPA)
Yi, Zhou,Huang, Manna,Wan, Yiqian,Zhu, Xinhai
, p. 3911 - 3920 (2018/09/29)
A ligand-recyclable, environmentally benign heterogeneous catalyst system composed of CuI and polystyrene-supported N (-(4-(aminomethyl)naphthalen-1-yl)- N (-phenyl-1 H -pyrrole-2-carbohydrazide (PSAP) has been established for Ullmann type C-N coupling based on the homogeneous catalyst system N ′, N ′-diphenyl-1 H -pyrrole-2-carbohydrazide/CuI. This heterogeneous catalyst system maintained the catalytic effectiveness of the homogeneous catalyst. A variety of functionalized aryl bromides can be efficiently aminated with aryl amines and aliphatic amines with high selectivity for amines over alcohols. Moreover, a practical application of this catalyst system to promote the reaction of commercially available 4-methoxy-2-methylaniline and bromobenzene in 10 mmol scale, provided 2-methyl-4-methoxydiphenylamine (MMDPA) with 93% yield with the merit of the approach being simple operation for work-up and purification.
PREPARATION OF SECONDARY AMINES WITH ELECTROPHILIC N-LINCHPIN REAGENTS
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Page/Page column 101-102, (2018/12/13)
In one aspect, the present disclosure provides methods of preparing a secondary amine. In some embodiments, the secondary amine comprises two different groups or two identifical groups. Also provided herein are compositions for use in the preparation of the secondary amine.
Practical Singly and Doubly Electrophilic Aminating Agents: A New, More Sustainable Platform for Carbon-Nitrogen Bond Formation
Kattamuri, Padmanabha V.,Yin, Jun,Siriwongsup, Surached,Kwon, Doo-Hyun,Ess, Daniel H.,Li, Qun,Li, Guigen,Yousufuddin, Muhammed,Richardson, Paul F.,Sutton, Scott C.,Kürti, László
supporting information, p. 11184 - 11196 (2017/08/21)
Given the importance of amines in a large number of biologically active natural products, active pharmaceutical ingredients, agrochemicals, and functional materials, the development of efficient C-N bond-forming methods with wide substrate scope continues to be at the frontier of research in synthetic organic chemistry. Here, we present a general and fundamentally new synthetic approach for the direct, transition-metal-free preparation of symmetrical and unsymmetrical diaryl-, arylalkyl-, and dialkylamines that relies on the facile single or double addition of readily available C-nucleophiles to the nitrogen atom of bench-stable electrophilic aminating agents. Practical single and double polarity reversal (i.e., umpolung) of the nitrogen atom is achieved using sterically and electronically tunable ketomalonate-derived imines and oximes. Overall, this novel approach represents an operationally simple, scalable, and environmentally friendly alternative to transition-metal-catalyzed C-N cross-coupling methods that are currently used to access structurally diverse secondary amines.
