81265-89-6Relevant academic research and scientific papers
Synthesis, antiprotozoal activity, and cheminformatic analysis of 2-phenyl-2h-indazole derivatives
Aguilera-Perdomo, Jacobo David,Cortés-Benítez, Francisco,Cortés-Gines, Miguel,Del Angel, Kevin Samael Olascoaga,Pérez-Villanueva, Jaime,Palacios-Espinosa, Juan Francisco,Quintana-Salazar, Edgar A.,Rodríguez-Villar, Karen,Soria-Arteche, Olivia,Yépez-Mulia, Lilián
, (2021/05/28)
Indazole is an important scaffold in medicinal chemistry. At present, the progress on synthetic methodologies has allowed the preparation of several new indazole derivatives with interesting pharmacological properties. Particularly, the antiprotozoal activity of indazole derivatives have been recently reported. Herein, a series of 22 indazole derivatives was synthesized and studied as antiprotozoals. The 2-phenyl-2H-indazole scaffold was accessed by a one-pot procedure, which includes a combination of ultrasound synthesis under neat conditions as well as Cadogan’s cyclization. Moreover, some compounds were derivatized to have an appropriate set to provide structure-activity relationships (SAR) information. Whereas the antiprotozoal activity of six of these compounds against E. histolytica, G. intestinalis, and T. vaginalis had been previously reported, the activity of the additional 16 compounds was evaluated against these same protozoa. The biological assays revealed structural features that favor the antiprotozoal activity against the three protozoans tested, e.g., electron withdrawing groups at the 2-phenyl ring. It is important to mention that the indazole derivatives possess strong antiprotozoal activity and are also characterized by a continuous SAR.
Metal-free regioselective C-H amination for the synthesis of pyrazole-containing 2H-indazoles
Wang, Kai,Wei, Tingting,Zhang, Yujia,Hou, Jiahao,Bai, Renren,Xie, Yuanyuan
, p. 1787 - 1794 (2021/03/14)
A general and practical regioselective approach for the C-H amination of 2H-indazoles under transition-metal-free conditions was developed. A series of substrates were tested showing eminent functional group tolerance and affording the C-N functionalization products in good to excellent yields. Mechanism studies revealed that a radical process was involved in this transformation.
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
supporting information, 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
Tert-Butyl Hydroperoxide-Mediated Oxo-Sulfonylation of 2 H-Indazoles with Sulfinic Acid toward Indazol-3(2 H)-ones
Ghosh, Payel,Mondal, Susmita,Hajra, Alakananda
supporting information, p. 1086 - 1090 (2020/02/04)
A new and efficient oxo-sulfonylation protocol has been established for the synthesis of N-sulfonylated indazolones employing sulfinic acid as a sulfonylating agent using tert-butyl hydroperoxide (TBHP) under ambient air. A series of structurally diverse 1-sulfonylindazol-3(2H)-one derivatives were obtained in good yields. A radical reaction mechanism has been proposed for this transformation.
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.
Regioselective C3-H Trifluoromethylation of 2 H-Indazole under Transition-Metal-Free Photoredox Catalysis
Murugan, Arumugavel,Babu, Venkata Nagarjuna,Polu, Ashok,Sabarinathan, Nagaraj,Bakthadoss, Manickam,Sharada, Duddu S.
, p. 7796 - 7803 (2019/06/27)
Trifluoromethyl-substituted heteroarenes are biologically active compounds and useful building blocks. In this sequence, we have developed a visible-light-promoted regioselective C3-H trifluoromethylation of 2H-indazole under metal-free conditions, which
A General One-Pot Synthesis of 2H-Indazoles Using an Organophosphorus–Silane System
Schoene, Jens,Bel Abed, Hassen,Schmieder, Peter,Christmann, Mathias,Nazaré, Marc
supporting information, p. 9090 - 9100 (2018/06/29)
A simple and direct approach for the regioselective construction of the privileged 2H-indazole scaffold is described. The developed one-pot strategy involves phospholene-mediated N?N bond formation to access 2H-indazoles. The amount of organophosphorus reagent was minimized by recycling the phospholene oxide with organosilane reductants. Starting from functionalized 2-nitrobenzaldehydes and primary amines, a mild reductive cyclization, involving the use of commercially available phospholene oxide and silanes, delivered a wide variety of substituted 2H-indazoles in good to excellent yields.
Highly reusable support-free copper(II) complex of para-hydroxy-substituted salen: Novel, efficient and versatile catalyst for C─N bond forming reactions
Sharghi, Hashem,Aberi, Mahdi,Shiri, Pezhman
, (2017/09/30)
An air-stable, highly active and versatile method for C─N bond forming reactions is reported. Under mild conditions using a highly reusable support-free Cu(II)–salen complex, structurally diverse N-aryl-substituted compounds were obtained via direct C─N bond forming reaction of HN-heterocycles with aryl iodides or three-component C─N bond forming reaction of 2-bromobenzaldehyde, aniline derivatives and sodium azide in good to excellent yields. C─N bond forming reaction for benzimidazole derivatives was also performed in the presence of the catalyst under ambient conditions. A series of hybrid benzimidazoles bearing morpholine, tetrazole and quinoxaline backbones were produced using this method. All reactions were performed in short times under air. The Cu(II) catalyst could be reused up to eight times in the direct cross-coupling reaction of 9H–carbazole with iodobenzene without any decrease in its catalytic activity.
A Facile One-Step Synthesis of 2-Arylindazoles via Reductive Cyclization of N-(2-nitroarylidene)amines
Lin, Wei,Hu, Minghua,Feng, Xian,Cao, Chengpao,Huang, Zhibin,Shi, Daqing
, p. 1170 - 1174 (2015/08/06)
A mild and efficient synthesis of 2-arylindazole derivatives via the reductive cyclization of nitro-aryl substrates mediated by a low-valent titanium reagent (TiCl4/Sm/Et3N) has been developed. The attractive features of the current method include an N-N bond formation and the selective reduction of the =C-N bond and nitro group, both of which were easily achieved in one-pot by controlling the pH of the reaction mixture.
Regioselective synthesis of 2 H-indazoles using a mild, one-pot condensation-cadogan reductive cyclization
Genung, Nathan E.,Wei, Liuqing,Aspnes, Gary E.
supporting information, p. 3114 - 3117 (2014/06/23)
An operationally simple and efficient one-pot synthesis of 2H-indazoles from commercially available reagents is reported. Ortho-imino-nitrobenzene substrates, generated via condensation, undergo reductive cyclization promoted by tri-n-butylphosophine to afford substituted 2H-indazoles under mild reaction conditions. A variety of electronically diverse ortho-nitrobenzaldehydes and anilines were examined. To further extend the scope of the transformation, aliphatic amines were also employed to form N2-alkyl indazoles selectively under the optimized reaction conditions.
