- Environment-friendly and efficient synthesis of 2-aminobenzo-xazoles and 2-aminobenzothiazoles catalyzed by: Vitreoscilla hemoglobin incorporating a cobalt porphyrin cofactor
-
In this study, an environment-friendly and efficient artificial Vitreoscilla hemoglobin (VHb) for the synthesis of 2-aminobenzoxazoles and 2-aminobenzothiazoles has been reported. We demonstrate an expression-based porphyrin substitution strategy to produce VHb containing cobalt porphyrin instead of native hemin, which can catalyze the oxidative cyclization of corresponding 2-aminobenzoxazoles and 2-aminobenthiazoles with up to 97% yield and 4850 catalytic turnovers in water under aerobic conditions. Hence, we provide a green and mild method for the synthesis of 2-aminobenzoxazoles and 2-aminobenzothiazoles. In addition, we indicate the value of porphyrin ligand substitution as a strategy to tune and enhance the catalytic properties of hemoproteins in non-natural reactions.
- Li, Fengxi,Li, Zhengqiang,Su, Jiali,Wang, Chunyu,Wang, Ciduo,Wang, Lei,Xu, Yaning,Zhao, Nan
-
p. 8047 - 8052
(2021/11/01)
-
- Switchable and Scalable Heteroarylation of Primary Amines with 2-Chlorobenzothiazoles under Transition-Metal-Free and Solvent-Free Conditions
-
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.
- 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)
-
- A practical synthesis of 2-aminobenzothiazoles via copper(I)-catalyzed tandem reaction of 2-iodoanilines with isothiocyanates in ionic liquids
-
A copper(I)-catalyzed tandem reaction of 2-iodoanilines with isothiocyanates was achieved in hydrophobic [bmim][PF6] ionic liquid under mild conditions, generating a variety of 2-aminobenzothiazoles in good to excellent yields. The tandem reaction that was carried out in [bmim][PF6] has some obvious advantages such as accelerated reaction rate and increased yield as compared with the reaction run in volatile solvents such as toluene. Furthermore, the CuI/1,10-phenanthroline catalytic system can be reused up to eight times without loss of activity and efficiency.
- Chen, Ling,Huang, Bin,Nie, Quan,Cai, Mingzhong
-
p. 446 - 450
(2016/05/19)
-
- A Synthesis of Benzothiazoles and Indoles by Direct C(sp2)-I Activation Catalyzed by Copper(II) on Silica-Coated Magnetite Nanoparticles
-
N-Substituted 2-amino-1,3-benzothiazoles and 2,3-disubstituted indoles were prepared by C-S and C-C cross-coupling reactions of 2-iodoanilines with isothiocyanates or 1,3-dicarbonyl compounds, respectively, in the presence of magnetic nanoparticles functionalized with a copper(II)-Schiff base complex as an efficient and reusable catalyst.
- Moghadam, Faeze Kiani,Jarrah, Najmeh,Mashayekh-Salehi, Ali,Ghanbaripour, Rashid
-
p. 1665 - 1668
(2016/07/06)
-
- Dithiocarbamate promoted practical synthesis of N-Aryl-2-aminobenzazoles: Synthesis of novel Aurora-A kinase inhibitor
-
Various N-aryl-2-aminobenzoxazoles and N-aryl-2-aminobenzothiazoles were synthesized from o-aminophenol and o-aminothiophenol, respectively, mediated by dithiocarbamate in one step. The salient features of this method include mild reaction condition, high
- Katari, Naresh Kumar,Venkatanarayana,Srinivas, Kummari
-
p. 447 - 453
(2015/05/20)
-
- Straightforward synthesis of 2-anilinobenzoxazoles and -benzothiazoles via mechanochemical ball-milling-promoted one-pot reactions
-
Under mechanochemical ball-milling and solvent-free conditions, a series of 2-anilinobenzoxazoles and -thiazoles were synthesized directly from the one-pot reaction of anilines, CS2, and 2-aminophenol and -thiophenol. This protocol exhibits the
- Zhang, Ze,Wang, Fang-Jian,Wu, Hao-Hao,Tan, Ya-Jun
-
supporting information
p. 440 - 441
(2015/05/27)
-
- Oxidative coupling of formamides with β-dicarbonyl compounds and the synthesis of 2-aminobenzothiazole using Cu(II)-functionalized Fe3O4 nanoparticles This article is dedicated to memory of Mostafa Chamran.
-
The Fe3O4@EDTA-Cu(II) nanoparticles catalyzed oxidative coupling of formamides with β-dicarbonyl compounds is developed using tert-butyl hydroperoxide as an oxidant. In general, the enol carbamates are synthesized in excellent yields (up to 92%) under the optimized reaction conditions. Fe3O4@EDTA-Cu(II) has the advantage of being magnetically recoverable. Also, we have established a highly efficient Fe3O4@EDTA-Cu(II)-catalyzed tandem reaction of 2-iodoanilines with isothiocyanates for the synthesis of 2-aminobenzothiazoles.
- Azizi, Kobra,Karimi, Meghdad,Heydari, Akbar
-
p. 812 - 816
(2015/02/19)
-
- Ligand- and solvent-free synthesis of 2-aminobenzothiazoles by copper-catalyzed tandem reaction of 2-haloanilines with isothiocyanates
-
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
- Yao, Ruiya,Liu, Haiyi,Wu, Yichao,Cai, Mingzhong
-
p. 109 - 113
(2013/03/13)
-
- A new and efficient synthesis of 2-aminobenzothiazoles derivatives from o-nitroaniline
-
A novel sy nthesis of 2-aminobenzothia zoles from a transition-met al-free reaction between aryl isothioc yanates and o-nitroaniline in the presence of K2CO3 is reported. The newly developed method is an efficient and cost-effective approach to synthesise 2-aminobenzothiazoles.
- Mirza, Behrooz,Mirzazadeh, Roghieh,Zeeb, Mohsen
-
p. 778 - 779
(2014/01/23)
-
- An "on-water" exploration of CuO nanoparticle catalysed synthesis of 2-aminobenzothiazoles
-
An "on-water" one-pot process has been engineered for the preparation of 2-aminobenzothiazole from ortho-halo (-F, -Cl, -Br and -I) substituted unsymmetrical thioureas. For ortho -I and -Br substrates the reactions afford 2-aminobenzothiazoles under metal free condition promoted by base. However, the relatively inert ortho -Cl and -F substrates undergo intramolecular arylthiolation only in the presence of CuO nanoparticles yielding 2-aminobenzothiazoles. This methodology provides easy access to aminobenzothiazoles utilising even the ortho -Cl and -F substrates. The catalyst is recyclable several times without loss of substantial activity. Other remarkable features include the wide range of functional group tolerance, absence of chromatographic purification (for ortho -I and -Br substrates) and providing moderate to excellent yield of the products under mild conditions, thus rendering the methodology as a highly eco-friendly alternative to the existing methods.
- Rout, Saroj Kumar,Guin, Srimanta,Nath, Jayashree,Patel, Bhisma K.
-
p. 2491 - 2498
(2013/02/21)
-
- A practical synthesis of 2-aminobenzothiazoles via the tandem reactions of 2-haloanilines with isothiocyanates catalyzed by immobilization of copper in MCM-41
-
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.
- Xiao, Ruian,Hao, Wenyan,Ai, Jinting,Cai, Ming-Zhong
-
experimental part
p. 44 - 50
(2012/04/17)
-
- An economically and environmentally sustainable synthesis of 2-aminobenzothiazoles and 2-aminobenzoxazoles promoted by water
-
Tandem reactions of isothiocyanates (1) with 2-aminothiophenols (2), or isothiocyanates (1) with 2-aminophenols (4), were carried out rapidly and efficiently in water. A significant rate acceleration of the reaction between 1a and 2a in water compared wit
- Zhang, Xinying,Jia, Xuefei,Wang, Jianji,Fan, Xuesen
-
supporting information; experimental part
p. 413 - 418
(2011/04/16)
-
- Iron-catalyzed tandem reactions of ortho-aminobenzenethiols with isothiocyanates leading to 2-aminobenzoazoles under ligand-and solvent-free conditions
-
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.
- Ding, Qiuping,Cao, Banpeng,Yang, Qin,Liu, Xianjin,Peng, Yiyuan
-
experimental part
p. 1782 - 1789
(2011/10/02)
-
- Iron-catalyzed one-pot synthesis of 2-aminobenzothiazoles from 2-aminobenzethiols and isothiocyanates under ligand-free conditions in water
-
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.
- Wang, Wenying,Zhong, Wenying,Zhou, Runxia,Yu, Jinsheng,Dai, Juan,Ding, Qiuping,Peng, Yiyuan
-
experimental part
p. 2841 - 2847
(2011/04/16)
-
- Synthesis of 2-aminobenzothiazole via FeCl3-catalyzed tandem reaction of 2-iodoaniline with isothiocyanate in water
-
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.
- Ding, Qiuping,Cao, Banpeng,Liu, Xianjin,Zong, Zhenzhen,Peng, Yi-Yuan
-
supporting information; experimental part
p. 1607 - 1610
(2010/12/19)
-
- Microwave-accelerated solvent- and catalyst-free synthesis of 4-aminoaryl/alkyl-7-chloroquinolines and 2-aminoaryl/alkylbenzothiazoles
-
An efficient synthesis of 4-aminoaryl/alkyl-7-chloroquinolines and 2-aminoaryl/alkylbenzothiazoles has been developed by microwave-accelerated regioselective aromatic nucleophilic substitution of 4,7-dichloroquinoline and 2-chlorobenzothiazole with aromatic and aliphatic amines under solvent-free conditions in the absence of any added protic or Lewis acid catalyst. Chemoselective reaction with the amino group in preference to the phenolic hydroxy group was observed. Thus, the treatment of 4,7-dichloroquinoline (1 equiv.) with a mixture of aniline (2 equiv.) and phenol (2 equiv.) afforded exclusive formation of 4-aminophenyl-7-chloroquinoline. When 4,7-dichloroquinoline (1 equiv.) was separately treated with 2-aminophenol (2 equiv.) and 4-aminophenol (2 equiv.), 4-(2'-hydroxyphenyl)-7-chloroquinoline and 4-(4'-hydroxyphenyl)-7-chloroquinoline, respectively, were formed. CSIRO 2007.
- Motiwala, Hashim F.,Kumar, Raj,Chakraborti, Asit K.
-
p. 369 - 374
(2008/02/11)
-