67058-59-7Relevant 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.
Synthesis of Benz-Fused Azoles via C-Heteroatom Coupling Reactions Catalyzed by Cu(I) in the Presence of Glycosyltriazole Ligands
Mishra, Nidhi,Singh, Anoop S.,Agrahari, Anand K.,Singh, Sumit K.,Singh, Mala,Tiwari, Vinod K.
supporting information, p. 389 - 399 (2019/05/06)
Glycosyl triazoles are conveniently accessible and contain multiple metal-binding units that may assist in metal-mediated catalysis. Azide derivatives of d-glucose have been converted to their respective aryltriazoles and screened as ligands for the synthesis of 2-substituted benz-fused azoles and benzimidazoquinazolinones by Cu-catalyzed intramolecular Ullmann type C-heteroatom coupling. Good to excellent yields for a variety of benz-fused heterocyles were obtained for this readily accessible catalytic system.
Copper/N,N,N',N'-tetramethylethylenediamine-catalyzed synthesis of N-substituted benzoheterocycles via C-S cross-coupling at ambient temperature in water
Zhao, Na,Liu, Liang,Wang, Fei,Li, Jia,Zhang, Wu
supporting information, p. 2575 - 2579 (2014/09/17)
Copper/N,N,N',N'-tetramethylethylenediamine (Cu/TMEDA)-catalyzed ambient temperature tandem reactions of isothiocyanates with 2-iodophenols or 2-iodoanilines in water without the protection of an inert atmosphere are described, which provide a simple, rapid, environmental method for the synthesis of a variety of 2-iminobenzo-1, 3- oxathioles and 2-aminobenzothiazoles in good yields. More important, the present reaction process needs only low amounts of copper catalyst (1mol%) and can yield the products on a gram scale.
Ligand- and solvent-free synthesis of 2-aminobenzothiazoles by copper-catalyzed tandem reaction of 2-haloanilines with isothiocyanates
Yao, Ruiya,Liu, Haiyi,Wu, Yichao,Cai, Mingzhong
, p. 109 - 113 (2013/03/13)
We report an environmentally friendly, efficient and practical method for the synthesis of 2-aminobenzothiazoles by a copper(II)-catalyzed tandem reaction of 2-haloanilines with isothiocyanates under ligand- and solvent-free conditions in air. The developed methodology conforms to the principles of 'green chemistry' and addresses the shortage of such methods for the synthesis of 2-aminobenzothiazoles. The reaction is quite general and generates a variety of 2-aminobenzothiazoles in good to excellent yields. Copyright
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.
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
experimental part, 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.
1,10-Phenanthroline-catalyzed tandem reaction of 2-iodoanilines with isothiocyanates in water
Zhang, Wu,Yue, Yun,Yu, Dan,Song, Lei,Xu, Yang-Yang,Tian, Yu-Jie,Guo, Yu-Jun
supporting information, p. 2283 - 2287 (2012/11/07)
The 1,10-phenanthroline-catalyzed tandem reaction of 2-iodoaniline with isothiocyanate in water is described, which provides an environmentally benign, efficient and simple route for the preparation of 2-aminobenzothiazoles. The present tandem process shows broad substrate scope in the absence of transition metals and phase-transfer catalysts. Copyright
A practical synthesis of 2-aminobenzothiazoles via the tandem reactions of 2-haloanilines with isothiocyanates catalyzed by immobilization of copper in MCM-41
Xiao, Ruian,Hao, Wenyan,Ai, Jinting,Cai, Ming-Zhong
experimental part, p. 44 - 50 (2012/04/17)
The heterogeneous tandem reactions of 2-haloanilines with isothiocyanates were achieved in DMSO using Et3N as base at 80 °C in the presence of a 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized copper(II) complex [MCM-41-2N-CuSO4], yielding a variety of 2- aminobenzothiazoles in good to excellent yields. This heterogeneous copper catalyst exhibited higher activity than CuSO4 and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity.
Copper-catalyzed tandem reactions of 2-halobenzenamines with isothiocyanates under ligand- and base-free conditions
Guo, Yan-Jin,Tang, Ri-Yuan,Zhong, Ping,Li, Jin-Heng
supporting information; experimental part, p. 649 - 652 (2010/04/23)
A ligand-free copper-catalyzed reaction of 2-halobenzenamines with isothiocyanates has been developed for the synthesis of 2-aminobenzothiazoles. In the presence of CuBr and TBAB (tetra-n-butyl ammonium bromide, additive), a variety of 2-halobenzenamines underwent the reaction with isothiocyanates at 40 °C, affording 2-aminobenzothiazoles in moderate to excellent yields. It is noteworthy that the reaction is conducted under mild, relatively low catalyst loading, and ligand- and base-free conditions.
Synthesis of 2-aminobenzothiazole via FeCl3-catalyzed tandem reaction of 2-iodoaniline with isothiocyanate in water
Ding, Qiuping,Cao, Banpeng,Liu, Xianjin,Zong, Zhenzhen,Peng, Yi-Yuan
supporting information; experimental part, p. 1607 - 1610 (2010/12/19)
An FeCl3-catalyzed tandem reaction of 2-iodoaniline with isothiocyanate in water is described, which provides an environmentally benign, efficient, and practical route for the generation of 2-aminobenzothiazole. This present tandem process shows broad substrate scope in the presence of octadecyltrimethylammonium chloride as a phase-transfer catalyst. In addition, the reaction media can be recovered and recycled without loss of efficiency.
