86-74-8Relevant articles and documents
Metal-Free Hydroxymethylation of Indole Derivatives with Formic Acid as an Alternative Way to Indirect Utilization of CO2
Huang, Wen-Bin,Yang, Meng,He, Liang-Nian
, p. 3775 - 3779 (2022/02/10)
The selective N-alkylation of indole substrates remains an ongoing research challenge for the relative attenuated nucleophilicity toward nitrogen. Herein, we developed the hydroxymethylation of indole derivatives to afford N-alkylated indole products with
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.
The benzyl can be selectively removed by visible light or near visible light. Method for protecting allyl and propargyl group
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Paragraph 0020, (2021/10/16)
The invention provides a method for selectively removing benzyl, allyl and propargyl protecting groups by visible light or near visible light, namely a substrate containing benzyl, allyl or propargyl protecting groups. The method has the advantages of simple operation, safe and clean visible light or near visible light as excitation conditions, cheap and easily available reagents, high reaction yield, high reaction chemistry and regional selectivity, and is suitable for selective removal of benzyl, allyl and propargyl protecting groups in various substrates.
Convenient One-Pot Synthesis of 9 H -Carbazoles by Microwave Irradiation Employing a Green Palladium-Based Nanocatalyst
Steingruber, H. Sebastián,Mendioroz, Pamela,Volpe, María A.,Gerbino, Darío C.
, p. 4048 - 4058 (2021/08/03)
An efficient palladium-catalyzed tandem reaction for the one-pot synthesis of 9 H -carbazoles under microwave irradiation is developed. This approach involves a sequential Buchwald-Hartwig amination and a direct arylation from affordable and inexpensive anilines and 1,2-dihaloarenes. For the development of this purpose, a novel and magnetically recoverable palladium nanocatalyst supported on a green biochar under ligand-free conditions is used. Compared to other existing palladium-based protocols, the present synthetic methodology shows a drastic reduction in reaction times and excellent compatibility with different functional groups allowing to obtain a small library of 9 H -carbazoles in high yields and with good regioselectivity. This procedure represents the first example in the direct synthesis of carbazoles using a heterogeneous palladium nanocatalyst from commercial precursors. To examine the application of this protocol, a direct and scalable synthesis of the bioactive carbazole alkaloid clausenalene from commercially available starting materials is described.
Method for synthesizing organic aromatic nitrogen-containing compound by taking nitrogen as nitrogen source
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Paragraph 0046-0051, (2021/05/08)
The invention provides a method for synthesizing an organic aromatic nitrogen-containing compound by taking nitrogen as a nitrogen source, and belongs to the field of organic synthesis. The invention provides a method for synthesizing an organic aromatic nitrogen-containing compound by taking nitrogen as a nitrogen source, which is characterized by comprising the following steps of: 1, reducing nitrogen by lithium powder to form lithium nitride; and 2, reacting the lithium nitride with a halogenated aromatic compound under the action of a transition metal catalyst, a ligand, alkali and a phase transfer catalyst to obtain an organic aromatic nitrogen-containing compound; wherein the two steps of reactions are completed in one pot. The method realizes the conversion of cheap nitrogen to the high-added-value aromatic nitrogen-containing compound, and also has the advantages of mild reaction conditions, good compatibility of substrate functional groups, high yield and the like.
Alkyl chain regulation: distinctive odd-even effects of mechano-luminescence and room-temperature phosphorescence in alkyl substituted carbazole amide derivatives
Che, Weilong,Li, Shuhui,Li, Xiaoning,Li, Zhen,Tu, Liangjing,Xie, Yujun
supporting information, p. 12124 - 12132 (2021/09/30)
A series of carbazole amide derivatives were synthesized by adjusting then-alkyl chain with different lengths from methyl to octyl (CAC-N,N= 1-8). Their photophysical behaviors were highly dependent on the parity of their alkyl chain. That is, compounds with even-numbered alkyl chains exhibited efficient mechanoluminescence (ML) and strong room temperature phosphorescence (RTP), however, no ML and inferior RTP were observed in the odd-numbered counterparts. To make the results more clear, the important starting material, carbazole, was synthesized in the lab, from which, all the above eight carbazole amide derivatives were re-synthesized for comparison. Although RTP properties were disturbed by impurities in commercial carbazole, the ML property remained unchanged. Single crystal analyses revealed that the crosslink network and isolated dimers were formed in even- and odd-numbered CAC crystals respectively through hydrogen-bond interactions, which should account for the odd-even alternating ML phenomena. Additionally, multicolor ML from blue to red was realized by doping various organic dyes in the ML host matrix of CAC-8. To the best of our knowledge, this work is the first observation of parity effects in the ML property.
Preparation method of 3 - bromo - N - phenyl carbazole
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Paragraph 0024; 0028-0029; 0039; 0043-0044, (2021/10/11)
The invention relates to a preparation method of 3 -bromo - N -phenyl carbazole, and belongs to the technical field of organic chemistry. To the invention, diphenylamine serves as a starting raw material, and 2 -bromophenylaniline is obtained through bromination reaction. Then, intramolecular cyclization is carried out to obtain carbazole. Then, 3 - bromocarbazole is obtained by bromination reaction. Finally, a substituted 3 - bromo - N -phenyl carbazole is obtained. By controlling the concentration and reaction environment of the reactants, the selectivity of the reaction site is effectively improved, the used raw materials are simple and easy to obtain, the preparation period is relatively short, and the reaction process is simple and easy to control.
Quinoline Ligands Improve the Classic Direct C?H Functionalisation/Intramolecular Cyclisation of Diaryl Ethers to Dibenzofurans
Mackey, Katrina,Jones, David J.,Pardo, Leticia M.,McGlacken, Gerard P.
supporting information, p. 495 - 498 (2021/01/12)
The C?H functionalisation approach to the synthesis of dibenzofurans is hampered by a number of problems. Herein we describe the evolution of a cheap, bench stable quinoline ligand, which obviates most of the current limitations and allows for a high yielding synthesis of a range of valuable dibenzofurans. Dibenzofurans are important motifs in natural products and compounds with wide biological activity.
Electrochemical Palladium-Catalyzed Intramolecular C—H Amination of 2-Amidobiaryls for Synthesis of Carbazoles
Gao, Xinlong,Lei, Aiwen,Wang, Pan,Wang, Qingqing,Zhang, Heng,Zhang, Xiaojing
supporting information, p. 143 - 148 (2020/12/18)
The synthesis of carbazoles based on the electrochemical Pd-catalyzed intramolecular C—H amination of 2-amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions. The reaction can be carried out in undivided cell without the addition of external chemical oxidant. Besides good functional group compatibility, the desired carbazoles can be scaled up and modified easily. Compared with previous methods, this protocol affords a simple and sustainable avenue for the construction of carbazoles.
Visible-light-driven Cadogan reaction
Qu, Zhonghua,Wang, Pu,Chen, Xing,Deng, Guo-Jun,Huang, Huawen
supporting information, p. 2582 - 2586 (2021/03/09)
Visible-light-driven photochemical Cadogan-type cyclization has been discovered. The organic D-A type photosensitizer 4CzIPN found to be an efficient mediator to transfer energy from photons to the transient intermediate that breaks the barriers of deoxygenation in Cadogan reaction and enables a mild metal-free access to carbazoles and related heterocycles. DFT calculation results indicate mildly endergonic formation of the intermediate complex of nitrobiarenes and PPh3, which corresponds with experimental findings regarding reaction temperature. The robust synthetic capacity of the photoredox Cadogan reaction systems has been demonstrated by the viable productivity of a broad range of carbazoles and related N-heterocycles with good tolerance of various functionalities.
