539811-75-1Relevant academic research and scientific papers
Switchable and Scalable Heteroarylation of Primary Amines with 2-Chlorobenzothiazoles under Transition-Metal-Free and Solvent-Free Conditions
Cheng, Hua,Zhu, Yan-Qiu,Liu, Peng-Fei,Yang, Kai-Qiang,Yan, Jin,Sang, Wei,Tang, Xiao-Sheng,Zhang, Rui,Chen, Cheng
, p. 10288 - 10302 (2021/08/16)
2-Aminobenzothiazoles comprise a valuable structural motif, which prevails in versatile natural products and biologically active compounds. Herein, a switchable and scalable C-N coupling protocol was developed for the synthesis of these compounds from 2-chlorobenzothiazoles and primary amines. Gratifyingly, this protocol was achieved under transition-metal-free and solvent-free conditions. Moreover, introducing an appropriate amount of NaH completely switched the selectivity from mono- toward di-heteroarylation, and further investigations provided a rationale for this new finding. Furthermore, gram-scale synthesis of representative products 3a and 4a was realized by applying operationally simple and glovebox-free procedures, which revealed the practical usefulness of this work. Finally, evaluation of the quantitative green metrics provided evidence that our protocol was superior over the literature ones in terms of green chemistry and sustainability.
Air-stable palladium(0) phosphine sulfide catalysts for Ullmann-type C-N and C-O coupling reactions
Majumder, Arpi,Gupta, Ragini,Mandal, Mrinmay,Babu, Madhu,Chakraborty, Debashis
, p. 23 - 34 (2015/03/05)
This paper describes an efficient procedure for palladium(0)-catalyzed N-arylation and O-arylation of aryl halides by Ullmann-type cross coupling reaction under mild reaction conditions in a short reaction time. Two phosphine sulphide ligands and their corresponding Pd(0) complexes namely [Pd(p2S2)(dba)] and [Pd(pp3S4)(dba)], were synthesized, where p2S2 is 1,2-bis(diphenylphosphino)ethane disulfide, pp3S4 is tris[2-(diphenylphosphino)ethyl]phosphine tetrasulfide and dba is dibenzylideneacetone. Optimal reaction conditions were determined for the arylation reactions using iodobenzene and benzimidazole by varying temperature, solvent, base and catalyst loading. The cross coupling reactions were carried out taking iodobenzenes/bromobenzenes and a wide variety of substituted aryl amines/phenols/alcohols with different steric and electronic properties to afford the desired N-aryl amines/diaryl ethers/alkyl aryl ethers in good to excellent yield (70-94%).
Direct transition metal-free C-S bond formation: Synthesis of 2-aminobenzothiazole derivatives via base-mediated approach
Wang, Rui,Chen, Zhi,Yue, Liang,Pan, Wei,Zhao, Jun-Jie
, p. 4529 - 4531 (2012/09/22)
A general, efficient, and more practical protocol for the base-mediated intermolecular or intramolecular S-arylation leading to the 2-aminobenzothiazole derivatives is reported. Remarkably, all reactions were carried out under transition-metal-free conditions with good to excellent yields, rendering the methodology presented herein highly valuable from both environmental and economic points of view.
DDQ-promoted C-S bond formation: Synthesis of 2-aminobenzothiazole derivatives under transition-metal-, ligand-, and base-free conditions
Wang, Rui,Yang, Wen-Juan,Yue, Liang,Pan, Wei,Zeng, Hong-Yao
experimental part, p. 1643 - 1648 (2012/08/07)
A transition-metal-free method for the intramolecular S-arylation of o-halobenzothiaoureas via DDQ-mediated leading to the 2-aminobenzothiazole derivatives is reported. The reactions are performed at room temperature under ligand- and base-free conditions with good to excellent yields. Georg Thieme Verlag Stuttgart · New York.
Iron-catalyzed tandem reactions of ortho-aminobenzenethiols with isothiocyanates leading to 2-aminobenzoazoles under ligand-and solvent-free conditions
Ding, Qiuping,Cao, Banpeng,Yang, Qin,Liu, Xianjin,Peng, Yiyuan
experimental part, p. 1782 - 1789 (2011/10/02)
An efficient route to synthesize a variety of 2-aminobenzoazoles has been discovered. It involves the reaction of ortho-aminobenzenethiols with isothiocyanates via iron-catalyzed tandem addition-annulations process under ligand and solvent free conditions on silica gel surface. Copyright Taylor &Francis Group, LLC.
Iron-catalyzed one-pot synthesis of 2-aminobenzothiazoles from 2-aminobenzethiols and isothiocyanates under ligand-free conditions in water
Wang, Wenying,Zhong, Wenying,Zhou, Runxia,Yu, Jinsheng,Dai, Juan,Ding, Qiuping,Peng, Yiyuan
experimental part, p. 2841 - 2847 (2011/04/16)
A practical and efficient method for the synthesis of 2-aminobenzothiazoles has been developed via an iron-catalyzed one-pot tandem reaction. Various 2-aminobenzothiazoles were conveniently synthesized in moderate to excellent yields. It is highlighted that the reaction is conducted under ligand-free conditions in water. The Japan Institute of Heterocyclic Chemistry.
A new, efficient and recyclable lanthanum(III) oxide-catalyzed C-N cross-coupling
Murthy, S. Narayana,Madhav,Reddy, V. Prakash,Nageswar
supporting information; experimental part, p. 3241 - 3245 (2011/02/23)
A new and efficient protocol for the C-N cross-coupling of aryl halides with heteroaromatic amines in the presence of lanthanum(III) oxide (10 mol%) as a recyclable catalyst, N,N′-dimethylethylenediamine (DMEDA) (20 mol%) and potassium hydroxide (KOH) as a base in dimethyl sulfoxide (DMSO) at 110 °C has been developed. This inexpensive catalytic system is highly effective towards the amination of aryl halides with various nitrogen nucleophiles and is significantly tolerant towards other functional groups in the substrates. Copyright
