88590-00-5Relevant articles and documents
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.
Chiral Phosphoric Acid Catalyzed Atroposelective C?H Amination of Arenes
An, Qian-Jin,Li, Shaoyu,Tan, Bin,Wang, Yong-Bin,Xia, Wang,Xiang, Shao-Hua
supporting information, p. 6775 - 6779 (2020/03/19)
N-arylcarbazole structures are important because of their prevalence in natural products and functional OLED materials. C?H amination of arenes has been widely recognized as the most efficient approach to access these structures. Conventional strategies involving transition-metal catalysts suffer from confined substrate generality and the requirement of exogenous oxidants. Organocatalytic enantioselective C–N chiral axis construction remains elusive. Presented here is the first organocatalytic strategy for the synthesis of novel axially chiral N-arylcarbazole frameworks by the assembly of azonaphthalenes and carbazoles. This reaction accommodates broad substrate scope and gives atropisomeric N-arylcarbazoles in good yields with excellent enantiocontrol. This approach not only offers an alternative to metal-catalyzed C–N cross-coupling, but also brings about opportunities for the exploitation of structurally diverse N-aryl atropisomers and OLED materials.
Preparation method of carbazole ring-containing compound
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Paragraph 0071-0074, (2020/05/02)
The invention provides a preparation method of a carbazole ring-containing compound, comprising the following step: a compound shown as a formula I-1 is subjected to a reaction in an organic solvent in the presence of metal and/or metal salt by using triphenylphosphine as a reducing agent to generate a compound shown as the formula I. In the invention, the carbazole ring compound is prepared by taking triphenylphosphine as a reducing agent and utilizing a nitro compound to react under the cooperation of the co-reducing agent, so that the dosage of triphenylphosphine is reduced, the generationamount of dangerous solid wastes is reduced, the post-treatment is easy, and the reaction temperature can be greatly reduced and the reaction time can be greatly shortened while high product yield isensured.