7788-69-4Relevant academic research and scientific papers
Direct Formation of 2-Substituted 2 H-Indazoles by a Pd-Catalyzed Reaction between 2-Halobenzyl Halides and Arylhydrazines
Aljaar, Nayyef,Al-Noaimi, Mousa,Conrad, Jürgen,Beifuss, Uwe
, p. 1408 - 1418 (2021/01/14)
A direct and operationally simple method for the regioselective synthesis of 2-aryl-substituted 2H-indazoles is reported. The Pd-catalyzed reaction between easily available 2-bromobenzyl bromides and arylhydrazines employing Cs2CO3 as the base and t-Bu3PHBF4 as the ligand in DMSO at 120 °C in a sealed tube delivers the 2-substituted-2H-indazoles in a single synthetic step with yields up to 79%. The new method is based on a regioselective intermolecular N-benzylation followed by intramolecular N-arylation and oxidation.
Oxidant-Switched Palladium-Catalyzed Regioselective Mono- versus Bis-ortho-Aroylation of 1-Aryl-1H-indazoles with Aldehydes via C–H Bond Activation
Chaudhary, Sandeep,Jain, Mukesh,Joshi, Jyoti,Sharma, Richa,Yadav, Ravi Kant
, (2022/02/16)
A highly efficient oxidant-switched palladium-catalyzed regioselective C(sp2)–H/C(sp2)–H cross-dehydrogenative coupling (CDC) for direct mono/bis-ortho-aroylation of substituted 1-phenyl-1H-indazoles 1a–j with v
Cu(I)–N-heterocyclic carbene-catalyzed base free C–N bond formation of arylboronic acids with amines and azoles
Zhang, Maoyuan,Xu, Zengbing,Shi, Dabin
, (2020/12/25)
A new N-heterocyclic carbene (NHC) precursor of imidazolium chloride and its corresponding Cu(I)–NHC complex 1 was synthesized. The complex 1 was found to be a highly effective catalyst for Chan-Evans-Lam coupling of arylboronic acid with amines and azoles (including imidazole, pyrazole and triazole), without addition of base at room temperature. Various substituents on three substrates can be tolerated, giving the desired coupling products in good to excellent yields (62–94%). The method is practical and offers an alternative to the corresponding copper-catalyzed Chan-Evans-Lam process for the construction of C–N bonds.
A ligand-free copper-catalyzed strategy to the N-arylation of indazole using aryl bromides
Bai, Di-Xiang,Lim, Rachel Sin-Ee,Ng, Hui-Fen,Teo, Yong-Chua
supporting information, p. 1398 - 1405 (2021/03/08)
A simple and efficient strategy for the C–N cross-coupling of indazole with a variety of substituted aryl bromides is reported. Under the optimized conditions, a broad scope of N-arylated products were obtained in good to excellent yields (up to 87%) under the ligand-free conditions.
N -Arylation of (hetero)arylamines using aryl sulfamates and carbamates via C-O bond activation enabled by a reusable and durable nickel(0) catalyst
Dindarloo Inaloo, Iman,Majnooni, Sahar,Eslahi, Hassan,Esmaeilpour, Mohsen
, p. 13266 - 13278 (2020/10/07)
An effective and general aryl amination protocol has been developed using a magnetically recoverable Ni(0) based nanocatalyst. This new stable catalyst was prepared on Fe3O4@SiO2 modified by EDTA and investigated by FT-IR, EDX, TEM, XRD, DLS, FE-SEM, XPS, NMR, TGA, VSM, ICP and elemental analysis techniques. The reaction proceeded via carbon-oxygen bond cleavage of (hetero)aryl carbamates and sulfamates under simple and mild conditions without the use of any external ligands. This method demonstrated functional group tolerance in the N-arylation of various nitrogen-containing compounds as well as aliphatic amines, anilines, pyrroles, pyrazoles, imidazoles, indoles, and indazoles with good to excellent yields. Furthermore, the catalyst could be easily recovered by using an external magnetic field and directly reused at least six times without notable reduction in its activity. This journal is
“On Water” Palladium Catalyzed Direct Arylation of 1H‐Indazole and 1H‐7‐Azaindazole
Abbouchi, Abdelmoula El,Akssira, Mohamed,Bousmina, Mostapha,El Kazzouli, Sa?d,Gambouz, Khadija,Guillaumet, Gérald,Nassiri, Sarah,Suzenet, Franck
, (2020/07/02)
The C3 direct arylation of 1H-indazole and 1H-7-azaindazole has been a significant challenge due to the lack of the reactivity at this position. In this paper, we describe a mild and an efficient synthesis of new series of C3-aryled 1H-indazoles and C3-aryled 1H-7-azaindazoles via a C3 direct arylation using water as solvent. On water, PPh3 was effective as a ligand along with a lower charge of the catalyst Pd(OAc)2 (5 mol%) at 100 oC, leading to C3-aryled 1H-indazoles or C3-aryled 1H-7-azaindazoles in moderate to good yields.
Tunable Emission Color of Iridium(III) Complexes with Phenylpyrazole Derivatives as the Main Ligands for Organic Light-Emitting Diodes
Niu, Zhi-Gang,Han, Hua-Bo,Li, Min,Zhao, Zheng,Chen, Guang-Ying,Zheng, You-Xuan,Li, Gao-Nan,Zuo, Jing-Lin
, p. 3154 - 3164 (2018/09/25)
Seven cyclometalated iridium(III) complexes Ir1-Ir7 based on phenylpyrazole derivatives as main ligands and tetraphenylimidodiphosphinate (tpip) as the ancillary ligand were synthesized and fully characterized. The proligands of 1-[4-(trifluoromethyl)phenyl]-1H-pyrazole (cf3ppz, 2a), substituted phenyl-2H-indazole {2-phenyl-2H-indazole (h-1-pidz, 2b), 2-(4-fluorophenyl)-2H-indazole (f-1-pidz, 2c), and 2-[4-(trifluoromethyl)phenyl]-2H-indazole (cf3-1-pidz, 2d)}, and substituted phenyl-1H-indazole {1-phenyl-1H-indazole (h-7-pidz, 2e), 1-(4-fluorophenyl)-1H-indazole (f-7-pidz, 2f), and 1-[4-(trifluoromethyl)phenyl]-1H-indazole (cf3-7-pidz, 2g)} were prepared with good yields. The emission maxima of all Ir(III) complexes can be tuned from 453 to 576 nm with different photoluminescence quantum yields (10.4-70.9%) by varying the type of substituent on the different main ligand frameworks. The organic light-emitting diodes using Ir(III) complexes as the emitters with blue, bluish-green, and yellow colors exhibit a maximum current efficiency and an external quantum efficiency of 39.2 cd A-1 and 14.8%, respectively.
Syntheses of 1-aryl-5-nitro-1h-indazoles and a general one-pot route to 1-aryl-1h-indazoles
Annor-Gyamfi, Joel K.,Gnanasekaran, Krishna Kumar,Bunce, Richard A.
, (2018/03/30)
An efficient route to substituted 1-aryl-1H-indazoles has been developed and optimized. The method involved the preparation of arylhydrazones from acetophenone or benzaldehyde substituted by fluorine at C2 and nitro at C5, followed by deprotonation and nucleophilic aromatic substitution (SNAr) ring closure in 45–90%. Modification of this procedure to a one-pot domino process was successful in the acetophenone series (73–96%), while the benzaldehyde series (63–73%) required a step-wise addition of reagents. A general one-pot protocol for 1-aryl-1H-indazole formation without the limiting substitution patterns required for the SNAr cyclization has also been achieved in 62–78% yields. A selection of 1-aryl-1H-indazoles was prepared in high yield by a procedure that requires only a single laboratory operation.
A convenient and simple synthesis of N-arylpirrolopyrimidines using boronic acids and promoted by copper (II) acetate
Espinosa-Bustos, Christian,Villegas, Alondra,Salas, Cristian O.
, p. 63 - 73 (2017/06/19)
A convenient and simple synthesis of novel N-arylated 2,4-dichloro-7H-pyrrolo[2,3-d]pyrimidine using several aryl boronic acids and copper (II) acetate is described. The yields obtained for all derivatives are in the range of 45-70 % and this synthetic ap
Indazolium halides as efficient ligands for Pd-catalyzed Suzuki–Miyaura cross-coupling of aryl bromides with arylboronic acids
Chen, Qian,Mao, Zhuqing,Guo, Fang,Liu, Xiaoshuang
supporting information, p. 3735 - 3738 (2016/07/26)
The indazolium halides containing various N-substituents have been conveniently prepared and applied in the palladium-catalyzed Suzuki–Miyaura cross-coupling reactions of aryl bromides with arylboronic acids at mild reaction conditions. The cross-coupling reaction provides the desired products in good to high yields. The ease of synthesis and the modularity, and the broad range of aryl bromides and arylboronic acids make this type of ligand attractive and promising for transition metal catalysis.
