101554-05-6Relevant articles and documents
Microwave-assisted direct synthesis of 2-substituted benzoxazoles from carboxylic acids under catalyst and solvent-free conditions
Kumar, Raj,Selvam,Kaur, Gurmeet,Chakraborti, Asit K.
, p. 1401 - 1404 (2005)
A direct coupling of carboxylic acids with 2-aminophenol under microwave irradiation has been achieved leading to the synthesis of 2-substituted benzoxazoles under metal and solvent-free conditions. Aliphatic, aromatic and heteroaromatic carboxylic acids provide good yields. Benzoxazole formation takes place in the presence of chloro, methoxy, phenoxy, thiophenoxy, and α,β-unsaturated functionalities. In the case of dicarboxylic acids, the reaction proceeds via the formation of the corresponding anhydride with predominant formation of the mono-benzoxazole. Georg Thieme Verlag Stuttgart.
Elemental Sulfur-Promoted Benzoxazole/Benzothiazole Formation Using a C=C Double Bond as a One-Carbon Donator
Chen, Xuecheng,Han, Shiqing,Hu, Liang,Liu, Yafei,Luo, Yue,Pan, Bin,Peng, Yalan,Zhang, Jun,Zhang, Yurong
, p. 14485 - 14492 (2021/11/12)
An efficient method to assemble diverse benzoxazoles/benzothiazoles in good yields was developed via oxidative cyclization with 2-aminothiophenols or 2-iodoanilines as raw materials. In this protocol, elemental sulfur was used as the effective oxidant and C atoms on the C=C double bond were introduced as a one-carbon donator.
Elemental Sulfur-Promoted Oxidative Rearranging Coupling between o-Aminophenols and Ketones: A Synthesis of 2-Alkyl benzoxazoles under Mild Conditions
Nguyen, Thanh Binh,Retailleau, Pascal
supporting information, p. 3887 - 3890 (2017/07/26)
In the presence of N-methylpiperidine, elemental sulfur was found to act as excellent oxidant in promoting oxidative rearranging coupling between o-aminophenols and ketones. A wide range of 2-alkylbenzoxazoles was obtained under mild conditions.
Elemental sulfur mediated synthesis of benzoxazoles, benzothiazoles and quinoxalines: Via decarboxylative coupling of 2-hydroxy/mercapto/amino-anilines with cinnamic acids
Guntreddi, Tirumaleswararao,Vanjari, Rajeshwer,Kumar, Saurabh,Singh, Rahul,Singh, Neetu,Kumar, Promod,Singh, Krishna Nand
, p. 81013 - 81016 (2016/09/09)
An easy and practical method has been developed for the synthesis of 2-benzylbenzoxazoles and 2-benzylbenzothiazoles using sulfur mediated decarboxylative coupling of cinnamic acids with 2-hydroxyanilines and 2-mercaptoanilines respectively under metal- and solvent-free conditions. However, the reaction of 2-aminoanilines with cinnamic acids leads to the formation of 2-arylquinoxalines under the same set of reaction conditions. The transformation is versatile and compatible with a number of functional groups.
Exploration of 2-benzylbenzimidazole scaffold as novel inhibitor of NF-κB
Boggu, PullaReddy,Venkateswararao, Eeda,Manickam, Manoj,Kwak, Dajin,Kim, Youngsoo,Jung, Sang-Hun
, p. 1872 - 1878 (2016/04/05)
For finding the novel inhibitor of nuclear factor κB activity, a series of benzimidazole derivatives were rationally designed, synthesized and systematically studied for their in vitro activities against LPS induced NF-κB inhibition in RAW 264.7 cells using the SEAP assay based on the flexible chalcone JSH ((E)-1-(2-hydroxy-6-(isopentyloxy)phenyl)-3-(4-hydroxy phenyl)prop-2-en-1-one) which was previously reported. Although most of the benzimidazole derivatives showed strong inhibitory activity in low micromolar potency, 2-(4-methoxybenzyl)-1H-benzo[d]imidazole (3m; IC50 = 1.7 μM) and 2-(2-methoxybenzyl)-1H-benzo[d]imidazole (3n; IC50 = 2.4 μM) showed the best inhibition. The structure activity relationship revealed that 2-benzylbenzimidazole scaffold with hydrogen bonding acceptor on phenyl ring appears as a pharmacophore.
N-heterocyclic carbene-Pd(II)-1-methylimidazole complex catalyzed C-H bond benzylation of (benzo)oxazoles with benzyl chlorides
Ji, Ya-Yun,Zhang, Yu,Hu, Yuan-Yuan,Shao, Li-Xiong
, p. 6818 - 6823 (2015/08/24)
The first example of phosphine-free, NHC-Pd(II) complex catalyzed direct C-H bond benzylation of (benzo)oxazoles with benzyl chlorides was reported in this paper. Under the suitable conditions, all reactions worked well enough to give the desired C2-benzylated products in good to almost quantitative yields, providing a facile and straight pathway for the C-H bond benzylation of (benzo)oxazoles within short time.
Trichloroisocyanuric Acid/Triphenylphosphine-Mediated Synthesis of Benzimidazoles, Benzoxazoles, and Benzothiazoles
Rezazadeh, Soodabeh,Akhlaghinia, Batool,Razavi, Nasrin
, p. 145 - 155 (2015/05/05)
A new and efficient method for preparation of benzimidazoles, benzoxazoles, and benzothiazoles from reactions of different carboxylic acids with o-phenylenediamine, o-aminophenol, and o-aminothiophenol in the presence of triphenylphosphine/trichloroisocyanuric acid system is presented. The desired products have been characterised on the basis of spectral (infrared, NMR, mass spectrometry) data, and the mechanism of their formation is proposed. The remarkable advantages are the inexpensive and readily available reagent, simple procedure, mild conditions, and good-to-excellent yields.
Rhodium-catalyzed synthesis of unsymmetrical di(aryl/heteroaryl)methanes using aryl/heteroarylmethyl ketones via CO-C bond cleavage
Li, Guangzhe,Arisawa, Mieko,Yamaguchi, Masahiko
supporting information, p. 4328 - 4330 (2014/04/17)
RhH(PPh3)4 and 1,2-bis(diphenylphosphino)benzene catalyze the reaction of aryl/heteroarylmethyl ketones and aryl heteroaryl ethers giving unsymmetrical diarylmethanes containing one or two heteroarenes in high yields. The reaction do
Palladium-catalyzed selective C-H benzylation towards functionalized azoles with a quaternary carbon center
Xie, Pan,Huang, Hanmin,Xie, Yinjun,Guo, Shengmei,Xia, Chungu
supporting information; experimental part, p. 1692 - 1700 (2012/08/14)
The direct C-H benzylation of azoles with benzyl chlorides proceeds efficiently, via sequential cleavage of one sp2 C-H bond and two sp3 C-H bonds in the presence of a palladium catalyst, to generate a wide range of tribenzylated azoles with a quaternary carbon center efficiently. The same catalyst could also promote the mono- and di-benzylation reactions through fine turning of the base and reaction conditions. Copyright
Palladium-catalyzed direct benzylation of azoles with benzyl carbonates
Mukai, Tomoya,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
supporting information; experimental part, p. 1360 - 1363 (2010/05/19)
"Chemical Equation Presented" The direct aromatic sp2 C-H benzylation of azole compounds with benzyl carbonates proceeds efficiently in the presence of a Pd2(dba)3/dppp catalyst system and KaOAc as a base to afford the corresponding diarylmethanes in good yields. In addition, the same palladium catalyst enables the direct benzylic sp3 C-H benzylation with the second benzyl carbonates without employing any external base.
