54184-69-9Relevant academic research and scientific papers
Metal-free, regioselective, visible light activation of 4CzIPN for the arylation of 2H-indazole derivatives
Saritha, Rajendhiran,Annes, Sesuraj Babiola,Ramesh, Subburethinam
, p. 14079 - 14084 (2021/04/22)
Highly regioselective organo photocatalysis of 4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) for the arylation of 2H-indazole is demonstrated. The present synthetic route provides a highly safe and easily accessible aniline precursor as an arylation reagent. The photoactivated 4CzIPN organocatalyst is found to be more efficient for single electron transfer without any organic base for the radical reaction. The carbazole-based photocatalyst (4CzIPN) with wide redox potential is stable and recyclable for further reaction transformations. Many indazole and aniline derivatives were used in the reaction and provided the arylated indazole derivatives in good to excellent yield.
Synthesis method of 2H-indazole and derivatives thereof
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Paragraph 0027-0040, (2020/12/15)
The invention discloses a synthetic reaction of 2H-indazole and derivatives thereof under a metal-free condition. The new strategy has the advantages of no metal participation, wide substrate range and good functional group compatibility, and an efficient
Efficient synthesis of 2-aryl-2: H -indazoles by base-catalyzed benzyl C-H deprotonation and cyclization
Gao, Wen-Xia,Jin, Guo-Qing,Liu, Miao-Chang,Wu, Hua-Yue,Zhou, Yun-Bing
, p. 14617 - 14620 (2020/12/02)
A straightforward and efficient method for the preparation of 2-aryl-2H-indazoles from ortho-alkyl substituted azoxybenzenes is presented. The reaction proceeds through base-catalyzed benzyl C-H deprotonation and cyclization to afford 2-aryl-2H-indazoles
Visible-light-mediated direct C3-arylation of 2: H -indazoles enabled by an electron-donor-acceptor complex
Aganda, Kim Christopher C.,Kim, Junyoung,Lee, Anna
supporting information, p. 9698 - 9702 (2019/12/02)
A mild visible-light-mediated, photocatalyst-free arylation of 2H-indazoles was developed. The formation of an electron donor-acceptor complex by 2H-indazoles and aryl diazonium salts in the presence of pyridine allows the direct arylation of 2H-indazoles under visible-light irradiation. This process provides an efficient route for the synthesis of C3-arylated-2H-indazoles, which are important scaffolds of various bioactive compounds.
Room-Temperature, Metal-Free, and One-Pot Preparation of 2H-Indazoles through a Mills Reaction and Cyclization Sequence
Kondo, Masaru,Takizawa, Shinobu,Jiang, Yuzhao,Sasai, Hiroaki
supporting information, p. 9866 - 9869 (2019/07/10)
The Mills reaction and cyclization of readily available 2-aminobenzyl alcohols and nitrosobenzenes using thionyl bromide provided 2H-indazoles in up to 88 % yields. In the metal-free process, acetic acid played a crucial role for the both Mills reaction and cyclization. A brominated 2H-indazole could also be obtained through the one-pot sequence.
Continuous-Flow Visible Light Organophotocatalysis for Direct Arylation of 2H-Indazoles: Fast Access to Drug Molecules
Vidyacharan, Shinde,Ramanjaneyulu, Bandaru T.,Jang, Seungwook,Kim, Dong-Pyo
, p. 2581 - 2586 (2019/06/17)
A continuous-flow homogeneous photocatalytic method has been devised for the direct arylation of 2H-indazoles. This visible-light-promoted approach directly accesses a wide range of structurally diverse C3-arylated scaffolds of biological interest in a fa
Tosyl Hydrazine-Promoted Tandem Condensation and Cyclization of Acyl Azobenzenes Enabling Access to 2H-Indazoles under Metal-Free Aerobic Conditions
Son, Jeong-Yu,Kim, Hyunseok,Baek, Yonghyeon,Um, Kyusik,Ko, Gi Hoon,Han, Gi Uk,Han, Sang Hoon,Lee, Kooyeon,Lee, Phil Ho
, p. 4354 - 4361 (2018/10/02)
Tosyl hydrazine-promoted tandem condensation and cyclization of 2-acyl azobenzenes under metal-free aerobic conditions was demonstrated to give 2-aryl-2H-indazoles having alkyl- or aryl groups at the 3-position in quantitative yields through the release o
Synthesis and biological evaluation of 2H-indazole derivatives: Towards antimicrobial and anti-inflammatory dual agents
Pérez-Villanueva, Jaime,Yépez-Mulia, Lilián,González-Sánchez, Ignacio,Palacios-Espinosa, Juan Francisco,Soria-Arteche, Olivia,Del Rosario Sainz-Espu?es, Teresita,Cerbón, Marco A.,Rodríguez-Villar, Karen,Rodríguez-Vicente, Ana Karina,Cortés-Gines, Miguel,Custodio-Galván, Zeltzin,Estrada-Castro, Dante B.
, (2017/11/20)
Indazole is considered a very important scaffold in medicinal chemistry. It is commonly found in compounds with diverse biological activities, e.g., antimicrobial and anti-inflammatory agents. Considering that infectious diseases are associated to an inflammatory response, we designed a set of 2H-indazole derivatives by hybridization of cyclic systems commonly found in antimicrobial and anti-inflammatory compounds. The derivatives were synthesized and tested against selected intestinal and vaginal pathogens, including the protozoa Giardia intestinalis, Entamoeba histolytica, and Trichomonas vaginalis; the bacteria Escherichia coli and Salmonella enterica serovar Typhi; and the yeasts Candida albicans and Candida glabrata. Biological evaluations revealed that synthesized compounds have antiprotozoal activity and, in most cases, are more potent than the reference drug metronidazole, e.g., compound 18 is 12.8 times more active than metronidazole against G. intestinalis. Furthermore, two 2, 3-diphenyl-2H-indazole derivatives (18 and 23) showed in vitro growth inhibition against Candida albicans and Candida glabrata. In addition to their antimicrobial activity, the anti-inflammatory potential for selected compounds was evaluated in silico and in vitro against human cyclooxygenase-2 (COX-2). The results showed that compounds 18, 21, 23, and 26 display in vitro inhibitory activity against COX-2, whereas docking calculations suggest a similar binding mode as compared to rofecoxib, the crystallographic reference.
Rh(III)-Catalyzed [4 + 1]-Annulation of Azoxy Compounds with Alkynes: A Regioselective Approach to 2H-Indazoles
Long, Zhen,Yang, Yudong,You, Jingsong
supporting information, p. 2781 - 2784 (2017/06/07)
A rhodium-catalyzed regioselective C-H activation/cyclization of azoxy compounds with alkynes has been disclosed to construct a variety of 2H-indazoles. A [4 + 1]-cycloaddition rather than a normal [4 + 2] mode is observed in the process of cyclative capture along with an oxygen-atom transfer and a C≡C triple bond cleavage. This protocol features a broad substrate scope, a good functional group tolerance, and an exclusive regioselectivity.
Direct Access to Acylated Azobenzenes and Amide Compounds by Reaction of Azoarenes with Benzylic Ethers as Acyl Equivalents
Hong, Gang,Aruma, Alfred Njasotapher,Zhu, Xiaoyan,Wu, Shengying,Wang, Limin
, p. 1147 - 1158 (2016/05/11)
Described herein is the use of N=N double bond of azobenzene as both directing group and radical acceptor in one-reaction protocol for the first time. An efficient pathway for the Pd-catalyzed regiospecific ortho-acylation of azoarenes using benzylic ethers as acyl equivalents has been achieved. In the absence of palladium catalyst, amide compounds were formed by the reaction of azoarenes with benzylic ethers under certain conditions. Various mono-acylazobenzene and amide compounds were obtained in good yields (35 examples). The mono-acylated products and amide products could be easily controlled by palladium catalyst.
