- Highly efficient one pot synthesis of benzimidazoles from 2-nitroaniline and PhSiH3 as reducing agent catalyzed by Pd/C as a heterogeneous catalyst
-
This work reports an efficient route for the synthesis of benzimidazole from o-nitroaniline in the presence of carbon dioxide atmosphere, PhSiH3 as a reducing agent catalyzed by Pd/C as a catalyst. Benzimidazoles have become the focus of organic chemists, as benzimidazole is an important intermediate in medicinal chemistry. We have developed more efficient route for the synthesis benzimidazole and various substituted benzimidazoles have been synthesized in good to excellent yield. The TBD (1,5,7-Triazabicyclo [4.4.0] dec-5-ene) is selected as a base as it promotes the CO2 insertion. Benzimidazoles were synthesized through reduction of nitro group followed by cyclization of amine using CO2 as a carbon source. Moreover, the Pd/C catalyst can be recycled up to five recycle run without significant changes in the yield of the product.
- Phatake, Vishal V.,Bhanage, Bhalchandra M.
-
-
- Ni-Catalyzed Dual C-H Annulation of Benzimidazoles with Alkynes for Synthesis of π-Extended Heteroarenes
-
Transition metal catalyzed dual C-H activation and annulation with alkynes was an attractive protocol to construct polycyclic π-extended structures. However, most of them were dominated by noble metal catalysts. Disclosed herein was the study of base-metal Ni-catalysis for dual C-H annulation of N-aromatic imidazole, which produced a range of desired polycyclic aza-quinolines in 48-95% yields. The use of bifunctional phosphine oxide ligand proved to be critical for success.
- Qi, Shao-Long,Li, Yue,Li, Jiang-Fei,Zhang, Tao,Luan, Yu-Xin,Ye, Mengchun
-
supporting information
p. 4034 - 4039
(2021/05/26)
-
- Immobilization of copper(II) into polyacrylonitrile fiber toward efficient and recyclable catalyst in Chan-Lam coupling reactions
-
A series of polyacrylonitrile fiber (PANF)-supported copper(II) catalysts were prepared through the immobilization of Cu(II) into prolinamide-modified PANF (PANPA-2F) and subsequently used for the synthesis of diverse N-arylimidazoles from arylboronic acids and imidazole. The prepared Cu(II)@PANPA-2Fs were well characterized by mechanical strength, FT-IR, XRD, XPS and SEM. Among them, CuCl2@PANPA-2F exhibited excellent catalytic performance, and its activity was significantly affected by the Cu loading. This catalytic system also displayed good activity in the synthesis of N-arylsulfonamides from arylboronic acids and tosyl azide. It was highly efficient in gram-scale reactions and could be reused five times. The advantages of low cost, easy preparation, good durability and facile recovery make the fiber catalyst attractive.
- Zhang, Chenlu,Zhu, Hai,Gang, Kaiyue,Tao, Minli,Ma, Ning,Zhang, Wenqin
-
-
- Copper quinolate: A simple and efficient catalytic complex for coupling reactions
-
We describe an effective and novel method to prepare N-aryl imidazoles via the copper quinolate-catalyzed N-arylation of aryl halides and imidazoles. A wide range of products were obtained in moderate to excellent yields under the optimal reaction conditions. Applying standard conditions, the model reaction could be performed on a gram scale. This method also presents a new avenue to the “click” reaction of terminal alkynes, benzyl bromide, and sodium azide and to the construction of C–C bonds by homocoupling of phenylboronic acid or phenylacetylene derivatives with the aid of copper quinolate.
- Wu, Fengtian,Li, Huiqin,Xie, Jianwei
-
-
- A Highly Active, Recyclable and Cost-Effective Magnetic Nanoparticles Supported Copper Catalyst for N-arylation Reaction
-
Abstract: The immobilization of a copper complex by covalent anchoring of 2-hydroxybenzophenone on the surface of amine-functionalized magnetic nanoparticles was reported. The structure and morphology of the catalyst was characterized by different techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron micrograph (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), vibrating sample magnetometer (VSM) and inductively coupled plasma (ICP) spectroscopy. This efficient and cost effective catalyst was applied in the N-arylation reaction and the products were obtained in good to excellent yields in short reaction times. The cost-effective catalyst demonstrated high stability, which could be facilely separated from the reaction mixture by applying an external magnet and recycled at least four times with only a slight decrease in its activity. Graphic Abstract: [Figure not available: see fulltext.]
- Zahedi, Razieh,Asadi, Zahra,Firuzabadi, Fahimeh Dehghani
-
-
- Cu(i) based catalysts derived from bidentate ligands and studies on the effect of substituents for: N -arylation of benzimidazoles and indoles
-
A family of Cu(i) complexes [Cu(L1-4)(Cl)(PPh3)] (C1-C4) were synthesized from bidentate ligands L1-L4 (where L1 = (E)-2-(2-benzylidene-1-phenylhydrazinyl)pyridine, L2 = (E)-N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)aniline, L3 = (E)-2-(2
- Kumari, Sheela,Ratnam, Anand,Mawai, Kiran,Chaudhary, Virendra Kumar,Mohanty, Aurobinda,Ghosh, Kaushik
-
p. 19591 - 19597
(2020/12/05)
-
- Efficient N-arylation of azole compounds utilizing selective aryl-transfer TMP-iodonium(III) reagents
-
It was determined that diaryliodonium(III) triflates bearing a trimethoxybenzene (TMP) auxiliary are more reactive than the reported selective aryl-transfer iodonium salts in the N-arylation of benzimidazoles and other types of azole compounds under catalytic conditions. The TMP-iodonium(III) salts can thus effectively facilitate the reaction at 50 °C or below, producing the corresponding N-arylated biaryls without the formation of TMP-derived coupling byproducts. Utilization of this TMP reagent under mild conditions would prevent the underlying problem of participation of the auxiliary group in the coupling reactions, which is observed while using the iodonium(III) salts that require elevated temperatures.
- Koseki, Daichi,Aoto, Erika,Shoji, Toshitaka,Watanabe, Kazuma,In, Yasuko,Kita, Yasuyuki,Dohi, Toshifumi
-
supporting information
p. 1281 - 1286
(2019/04/10)
-
- Chan-Lam cross-coupling reaction based on the Cu2S/TMEDA system
-
A catalyst based on the readily available Cu2S/TMEDA system using a stable copper(I) source was developed for the Chan-Lam cross-coupling reaction. The capability of the catalyst was demonstrated with 1H-benzo[d]imidazol-2(3H)-one, 1H-benzo[d]imidazole, and 1H-imidazole together with electron-deficient, electron-rich, and sterically demanding boronic acids at room temperature in the presence of atmospheric oxygen to give the cross-coupling products in moderate to excellent yields. In addition, the coupling reaction of 1H-benzo[d]imidazole with several pinacol or neopentylglycol boronates indicated further potential of the catalyst. The reaction conditions tolerate the hydroxyl and bromo functional groups. The catalytic system also enables to synthesize the mono-N-substituted anilines from primary aliphatic amines. However, the two model compounds for the secondary and aromatic amines, piperidine and aniline, do not react. Two sterically demanding products with the restricted C–N bond rotation, synthesized by the N-arylation of 1H-benzo[d]imidazol-2(3H)-one with o-tolylboronic acid, enabled to confirm the atropisomers prepared by the Chan-Lam cross-coupling reaction. Furthermore, an example of one-pot Chan-Lam and Suzuki-Miyaura reaction has been reported.
- Janíková, Kate?ina,Jedinák, Luká?,Volná, Tereza,Canka?, Petr
-
p. 606 - 617
(2018/01/01)
-
- Functional 1,8-naphthyridine copper(I) complex as efficient catalyst for n-arylation of imidazoles coupling reactions
-
The functional 1,8-naphthyridine copper(I) complex, synthesized through a non-catalyst C(sp3)-H methylenation, catalyzes the cross-coupling reaction of aryl halides with imidazoles, by C?N bond formation. The Cu(I) complex catalyzes the reaction with a low catalyst loading (1%, molar fraction) and cheap base even under aerobic conditions. The procedure tolerates aryl halides with various functional groups (such as methyl, methoxy, acetyl, fluoro, nitrile and nitro groups) and gives the corresponding coupling products in moderate to high yields.
- Gou, Gao-Zhang,Wu, Na,Zhang, Ju-Cheng,Shi, Ling,Liu, Gui-Yang,Liu, Wei,Mang, Chao-Yong,Chi, Shao-Ming
-
p. 181 - 185
(2018/02/28)
-
- N, O-Bidentate ligand-tunable copper(II) complexes as a catalyst for Chan-Lam coupling reactions of arylboronic acids with 1 H-imidazole derivatives
-
An efficient procedure for Chan-Lam coupling reactions of arylboronic acids with 1H-imidazole derivatives using N,O-bidentate ligand-tunable copper(ii) complexes as a catalyst under base-free conditions has been developed. This protocol features mild reac
- Jia, Xuefeng,Peng, Pai
-
p. 8984 - 8988
(2018/12/10)
-
- Base-assisted, copper-catalyzed N-arylation of (benz)imidazoles and amines with diarylborinic acids
-
N-Arylation of (benz)imidazoles and amines with diarylborinic acids as cost-effective aryl source has been efficiently effected via Cu(OAc)2-catalyzed Chan-Lam coupling in assistance of tetramethylethylenediamine (TMEDA) in methanol and pyridine (Py) in dichloromethane, respectively, in air at room temperature. The diarylborinic acids could be well accommodated by the Chan-Lam coupling oxidative conditions containing a proper combination of bases and solvents. The steric hindrance appeared to affect the copper-catalyzed N-arylation using the high-order arylboron reagent more significantly than the electronic factors, especially for low reactive anilines and aliphatic amines.
- Guan, Changwei,Feng, Yuanyuan,Zou, Gang,Tang, Jie
-
p. 6906 - 6913
(2017/11/03)
-
- CopperII phthalocyanine as an efficient and reusable catalyst for the N-arylation of nitrogen containing heterocycles
-
Copper phthalocyanine (CuIIPc) was found to be an efficient catalyst for the catalyzed N-arylation of N–H heterocycles with aryl iodides and bromides under mild reaction conditions. A variety of hindered and functionalized N–H heterocycles and aryl halides were successfully used as the substrates for the given catalytic reaction and were transformed in good to excellent yields.
- Yadav, Kumar Karitkey,Narang, Uma,Bhattacharya, Soumee,Chauhan, Shive M.S.
-
supporting information
p. 3044 - 3048
(2017/07/17)
-
- Cu2O/Cs2CO3/DMF: An efficient catalytic system for N-arylation of imidazole with aryl halides under ligand-free conditions
-
A ligand-free Cu-catalyzed protocol for the Ullmann-type N-arylation of N-containing heterocycles with aryl or heteroaryl iodides and bromides has been established. A broad range of functional groups is well tolerated on both of the cross-coupling partners, producing the desired products in good to excellent yields.
- Wang, Xiaochuang,Wang, Meiji,Xie, Jianwei
-
supporting information
p. 1797 - 1803
(2017/09/22)
-
- N-Arylation of nitrogen containing heterocycles with aryl halides using copper nanoparticle catalytic system
-
Cu nanoparticles promoted N-arylation of NH-heterocycles with aryl halides is an effective and inexpensive method. In this synthetic protocol, good to excellent yields are obtained. Both aryl iodide and aryl bromide are compatible with the reaction conditions.
- Pai, Gita,Chattopadhyay, Asoke P.
-
p. 3140 - 3145
(2016/07/06)
-
- Ethylene glycol, an efficient and recoverable medium for copper-catalyzed N-arylation of diazoles under microwave irradiation
-
Ethylene glycol was used as an efficient and recoverable medium for the reaction of diazoles with aryl iodides and aryl bromides in the presence of CuCl2 as the catalyst and K2CO3 as the base. Consequently, imidazole, benzimidazole, and pyrazole reacted readily under microwave irradiation to give good to excellent yields of their corresponding N-arylated products in relatively short time periods. Apparently, ethylene glycol plays a dual role by activating the catalyst and also providing a homogenous medium for the processes. The reaction medium consisting of the solvent, the base, and the copper salt was recovered and reused successfully in the next several reactions.
- Sharifi, Ali,Ghonouei, Nima,Abaee, M. Saeed
-
supporting information
p. 249 - 256
(2016/03/09)
-
- Green synthesis of CuO nanoflakes from copper pincer complex for effective N-arylation of benzimidazole
-
Nanostructured CuO is synthesized in water using copper pincer complex as precursor without any stabilizing agent and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-
- Jerome,Kausalya,Daniel Thangadurai,Karvembu
-
-
- Tamarix gallica leaf extract mediated novel route for green synthesis of CuO nanoparticles and their application for N-arylation of nitrogen-containing heterocycles under ligand-free conditions
-
We report the green synthesis of CuO nanoparticles (CuO NPs) using Tamarix gallica leaf extract and their catalytic activity for N-arylation of nitrogen-containing heterocycles with aryl halides under ligand-free conditions. Tamarix gallica leaves are used as a bio-material for the first time as reducing agent. The green synthesized CuO NPs was characterized using the powder XRD, TEM, UV-vis and FT-IR. This method offers several advantages, viz. high yields, simple methodology, recyclability of the catalyst and a simple workup procedure.
- Nasrollahzadeh, Mahmoud,Sajadi, S. Mohammad,Maham, Mehdi
-
p. 40628 - 40635
(2015/05/20)
-
- A simple and efficient 2N2O-Cu(II) complex as a catalyst for N-arylation of imidazoles in water
-
Four inexpensive and air- and moisture-stable 2N2O-Cu complexes were synthesized, one of which proved to exhibit good catalytic activity for the N-arylation of imidazoles in water. A variety of aryl iodides and aryl bromides underwent coupling with imidazoles promoted by the catalytic system with moderate to excellent yields.
- Liu, Yashuai,Gu, Ningning,Liu, Ping,Xie, Jianwei,Dai, Bin,Liu, Yan
-
p. 468 - 470
(2015/06/30)
-
- Open-air N-arylation of N-H heterocycles with arylboronic acids catalyzed by copper(II) Schiff base complexes
-
Two copper Schiff base complexes, in both homogeneous and heterogeneous forms, were prepared and characterized by using elemental analysis, FTIR, UV-Vis spectroscopy and scanning electron microscopy. The catalytic performances of these complexes were studied in the N-arylation of N-H heterocycles with arylboronic acids in methanol without any added base at 40 °C under open air. The effects of various parameters such as solvent and temperature on the reaction system were studied. The reaction is applicable to a wide variety of N-H heterocycles and arylboronic acids. The heterogeneous catalyst was recovered by simple filtration, and reusability experiments showed that this catalyst can be used five times without much loss in the catalytic activity.
- Islam,Dey, Ram Chandra,Roy, Anupam Singha,Paul, Sumantra,Mondal, Sanchita
-
p. 961 - 969
(2015/01/09)
-
- A simple and efficient copper(II) complex as a catalyst for N-arylation of imidazoles
-
Four inexpensive and air-/moisture-stable pyrrolecarbaldiminato-Cu complexes 1-4 were synthesized and evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides and activated aryl chlorides underwent the coupling with imidazoles, promoted by the catalyst 4, in moderate to good yields without the protection by an inert gas. Copyright
- Jiao, Yanli,Yan, Nannan,Xie, Jianwei,Ma, Xiaowei,Liu, Ping,Dai, Bin
-
p. 267 - 270
(2013/08/24)
-
- Iron(III)-catalyzed direct N-alkylation of azoles via oxidative transformation of sp3 ci£h bonds under solvent-free conditions
-
A new approach to synthesize N-alkylation of azoles by iron(III)-catalyst under solvent-free conditions was developed. The method is broad in scope and highly efficient. A new approach to synthesize N-alkylation of azoles by iron (III)-catalyst under solv
- Liu, Xiang,Chen, Yongxin,Li, Kangning,Wang, Dong,Chen, Baohua
-
p. 2285 - 2291,7
(2020/09/16)
-
- Catalyst-free N-arylation using unactivated fluorobenzenes
-
Caught in a 'SNAr'e: A one-step, high-yielding, catalyst-free method is described for N-arylation of azoles and indoles from unactivated monofluorobenzenes. This SNAr reaction tolerates a wide range of substituents and can also generate halogenated N-aryl products. The reaction can also be performed simultaneously with or subsequent to a copper- or palladium-catalyzed cross-coupling reaction in the same pot. Copyright
- Diness, Frederik,Fairlie, David P.
-
supporting information; experimental part
p. 8012 - 8016
(2012/09/05)
-
- New, simple, and effective thiosemicarbazide ligand for copper(II)-catalyzed N-arylation of imidazoles
-
A new methodology of copper-catalyzed coupling reaction has been developed, involving imidazoles react with aryl halides using CuCl2 ·H2O as catalyst and 1-(4- hydroxy-3-me thoxybenzylidene) thiosemicarbazide (L1) as ligand. It is th
- Shan, Yuefeng,Wang, Ying,Jia, Xiaolei,Cai, Wenwen,Xiang, Jiannan
-
experimental part
p. 1192 - 1199
(2012/04/17)
-
- Efficient and reusable catalytic system of Cul-PEG for n-arylation of imidazoles
-
A simple, efficient, and recyclable catalytic system of CuI-poly(ethylene glycol) (PEG) was developed for the N-arylation of imidazoles with aryl halides to afford corresponding N-arylimidazoles in good to excellent yields under mild conditions and free of any additional ligands and solvents. The isolation of the products was readily performed by simple extraction with ether, and the catalytic system could be reused without remarkable loss of activity even after six runs.
- Zhang, Qiang,Luo, Jun,Wei, Yunyang
-
experimental part
p. 114 - 121
(2011/11/01)
-
- Benzotriazol-1-ylmethanol: An excellent bidentate ligand for the copper/palladium-catalyzed C-N and C-C coupling reaction
-
An efficient benzotriazole based N,O bidentate ligands for the Cu-catalyzed N-arylation of π-excessive nitrogen heterocycles is described. This ligand accomplishes C-N coupling of Nheterocycles and C-C coupling of boronic acids with a variety of hindered, functionalized aryl/heteroaryl halides under mild reaction conditions in good to excellent yields. Using his ligand C-N and C-C (Suzuki) couplings with bromoarenes could be conducted with less catalyst loading. A wide array of deactivated and hindered aryl halides react cleanly to afford the functionalized biaryl derivatives in high yields. ARKAT-USA, Inc.
- Jha, Rajeev R.,Singh, Jaspal,Tiwari, Rakesh K.,Verma, Akhilesh K.
-
p. 228 - 248
(2013/02/23)
-
- A reusable polymer supported copper catalyst for the C-N and C-O bond cross-coupling reaction of aryl halides as well as arylboronic acids
-
A simple and industrially viable protocol for C-N and C-O coupling was reported here. The polymer supported heterogeneous copper catalyst was prepared from chloromethyl polystyrene using a simple procedure. O-Arylation of substituted phenols with various aryl halides was achieved using this copper catalyst in DMSO medium. This heterogeneous copper catalyst, also efficiently works for the N-arylation of N-H heterocycles with aryboronic acids in methanol. This catalyst was also effective in amination reaction of primary amines with aryl halides as well as arylboronic acids in DMSO medium. The effects of solvent, base and temperature for the O-Arylation and amination reactions were reported. Further, the catalyst can be easily recovered quantitatively by simple filtration and reused up to several times without sufficient loss of its catalytic activity.
- Islam, Sk.Manirul,Mondal, Sanchita,Mondal, Paramita,Roy, Anupam Singha,Tuhina,Salam, Noor,Mobarak, Manir
-
experimental part
p. 4264 - 4274
(2012/01/06)
-
- Cross-coupling reactions of aryl halides with amines, phenols, and thiols catalyzed by an N,N′-dioxide-copper(I) catalytic system
-
The coupling reactions of various N, O, and S nucleophilic reagents with aryl halides have been successfully carried out under mild conditions by using a novel chiral N,N′-dioxide-copper(I) catalytic system as the catalyst. This versatile and efficient catalyst system has been demonstrated to facilitate the cross-coupling reactions of aryl halides with amines, phenols, and thiols to afford the corresponding desired products in good to excellent yields.
- Yang, Haitao,Xi, Chao,Miao, Zhiwei,Chen, Ruyu
-
supporting information; experimental part
p. 3353 - 3360
(2011/08/03)
-
- A versatile and efficient cu-catalyzed N-Arylation of aromatic cyclic secondary amines with aryl halides
-
A copper-catalyzed coupling reaction of aryl halides with various aromatic cyclic secondary amines in DMSO has been developed efficiently. The versatile and efficient copper catalyst system is of wide-spread and practical application in cross-coupling reactions.
- Yang, Haitao,Miao, Zhiwei,Chen, Ruyu
-
experimental part
p. 325 - 331
(2012/05/31)
-
- Cu(OAc)2·H2O-catalyzed N-arylation of nitrogen-containing heterocycles
-
In the absence of any additional ligands, the efficient N-arylation of nitrogen-containing heterocycles with aryl iodides catalyzed by relative low catalyst amount of Cu(OAc)2·H2O was developed. This simple catalytic system is involved in the C-N cross-coupling reaction and works for a variety of pyrazole, pyrrole, imidazole, triazole, indole, benzoimidazole, benzotriazole, carbazole, and anilines as well as aryl iodides with different electronic properties. Highly efficient copper(II)-catalyzed N-arylation protocol was established.
- Xu, Zhong-Lin,Li, Hong-Xi,Ren, Zhi-Gang,Du, Wei-Yuan,Xu, Wei-Chang,Lang, Jian-Ping
-
supporting information; experimental part
p. 5282 - 5288
(2011/08/04)
-
- A reusable polymer supported copper(I) complex for the C-N bond cross-coupling reaction
-
The Ullmann coupling of amines with aryl iodide as well as arylboronic acids and N(H)-heterocycles with arylboronic acids has been carried out efficiently using PS-LCu(I) catalyst. The copper complex has been prepared and characterized by using scanning electron microscope (SEM), elemental analysis, atomic absorption spectroscopy (AAS), Thermo gravimetric analysis and spectrometric methods like Fourier transform infrared spectroscopy (FTIR). The effects of various parameters such as temperature, solvent and base on the reaction system were studied. The reusability experiments show that the catalyst can be used five times without much loss in the catalytic activity.
- Islam,Mondal, Sanchita,Mondal, Paramita,Roy, Anupam Singha,Tuhina, Kazi,Mobarok, Manir
-
experimental part
p. 1352 - 1357
(2011/10/12)
-
- An efficient recyclable polymer supported copper(II) catalyst for C-N bond formation by N-arylation
-
Polymer supported Cu(II) catalyst was prepared, characterized and employed for the N-arylation and amination reaction of N-H heterocycles with aryl halides as well as arylboronic acids to afford the corresponding coupled products in good to excellent yields. This catalyst can be used several times with consistent catalytic activity.
- Islam, Manirul,Mondal, Sanchita,Mondal, Paramita,Roy, Anupam Singha,Tuhina, Kazi,Mobarok, Manir,Paul, Sumantra,Salam, Noor,Hossain, Dildar
-
experimental part
p. 1171 - 1181
(2012/06/18)
-
- An efficient polymer-supported copper(II) catalyst for the N-arylation reaction of N(H)-heterocycles with aryl halides as well as arylboronic acids
-
Immobilization of copper onto polystyrene provided a polymer-supported copper(II) catalyst, which was effective in cross-coupling reactions between N-containing substrates and arylboronic acids using methanol as a solvent in air under base-free conditions
- Islam, Manirul,Mondal, Sanchita,Mondal, Paramita,Roy, Anupam Singha,Tuhina, Kazi,Salam, Noor,Paul, Sumantra,Hossain, Dildar,Mobarok, Manir
-
experimental part
p. 447 - 458
(2012/03/10)
-
- PEG3400-Cu2O-Cs2CO3: an efficient and recyclable microwave-enhanced catalytic system for ligand-free Ullmann arylation of indole and benzimidazole
-
A mild, simple and efficient microwave-enhanced copper-catalyzed protocol for N-arylation using high molecular weight poly(ethylene glycol) (PEG3400) as a solvent is reported. Indole and benzimidazole have been N-arylated in the presence of cup
- Colacino, Evelina,Villebrun, Laurent,Martinez, Jean,Lamaty, Frédéric
-
experimental part
p. 3730 - 3735
(2010/07/05)
-
- Copper(II) hydroxide complexes of N-heterocyclic carbenes and catalytic oxidative amination of arylboronic acids
-
Reactions of the imidazolium salts or their corresponding silver carbene complexes with copper powder afforded unusual copper(II) hydroxide complexes of N-heterocyclic carbenes: [Cu2(μ-OH)(L1)](PF6) 2 (2; L1 = 3,5-bis(N-picolylimidazolylidenylmethy1)pyrazolate), [Cu4(μ3-OH)2(L2)2](PF 6)4 (3; L2 = 3,5-bis(N-pyridylimidazolylidenylmethy1) pyrazolate), and [Cu4(μ3-OH)2(L3) 2](PF6)4 (4; L3 = 3,5-bis(N- pyrimidylimidazolylidenylmethy1)pyrazolate). The same reaction of 3,5-bis(N-thiophenylimidazoliumylmethy1)pyrazole yielded a dinuclear Cu(II)-NHC complex, [Cu2(L4)2] (PF6)2 (5; L4 = 3,5-bis(N-thiophenylimidazolylidenylmethy1)pyrazolate). The complexes have been fully characterized by X-ray diffraction analysis, elemental analysis, and IR and ESI-MS spectra. A catalytic study shows that complex 4 is highly active in the N-arylation reactions of imidazoles and aromatic amines with arylboronic acids in methanol at room temperature under base-free conditions.
- Liu, Bo,Liu, Bin,Zhou, Yongbo,Chen, Wanzhi
-
experimental part
p. 1457 - 1464
(2010/05/01)
-
- Cross coupling of arylboronic acids with imidazoles by sulfonatocopper(II) (salen) complex in water
-
A mild and clean protocol for the cross coupling reactions between imidazoles and arylboronic acids has been developed in good to excellent yields up to 98% in the presence of sulfonatocopper(II)(salen) catalyst in water without addition of other additives and bases.
- Wang, Lixia,Jiang, Zhaoqiong,Yu, Lintao,Li, Lili,Li, Zhengkai,Zhou, Xiangge
-
supporting information; experimental part
p. 764 - 765
(2011/01/11)
-
- Synthesis of 1-substituted benzimidazoles from o-bromophenyl isocyanide and amines
-
o-Bromophenyl isocyanide (1-Br) reacts with various primary amines under Cu1 catalysis to afford 1 -substituted benzimidazoles 4 in moderate to good yields (38-70%, 13 examples). Analogously, 2-b:romo-3-isocyanothiophene (6) furnishes-substituted 3H-thieno[2,3-d]imidazoles 7 (44-49%, 3 examples).
- Lygin, Alexander V.,De Meijere, Armin
-
experimental part
p. 5138 - 5141
(2010/01/03)
-
- A facile and efficient oxalyldihydrazide/ketone-promoted copper-catalyzed amination of aryl halides in water
-
A novel three-component catalyst CuO/oxalyldihydrazide/hexane-2,5-dione was a very convenient, economic, and effective catalytic system for the Ullmann-type C-N coupling reaction in water. Both aryl bromides and aryl iodides could be aminated by a variety of amines even at room temperature or with heating to afford very good isolated yields.
- Zhu, Xinhai,Su, Li,Huang, Liye,Chen, Gong,Wang, Jinlong,Song, Huacan,Wan, Yiqian
-
supporting information; experimental part
p. 635 - 642
(2009/07/17)
-
- Recyclable heterogeneous iron catalyst for C-N cross-coupling under ligand-free conditions
-
(Chemical Equation Presented) An efficient and ligand-free C-N cross-coupling of aryl halides with various heterocycles using Fe/Cg as a recyclable catalyst is reported. The yields are excellent to moderate. 2009 American Chemical Society.
- Swapna,Vijay Kumar,Prakash Reddy,Rama Rao
-
supporting information; experimental part
p. 7514 - 7517
(2009/12/28)
-
- A simple and efficient catalytic system for N-arylation of imidazoles in water
-
A study was conducted to develop a simple and efficient catalytic system for N-arylation of immidazoles in water. Demonstrations revealed that the catalytic system contained a number of significant advantages. Some of these advantages included the use of water as a green solvent in place of volatile organic solvents and the catalysis was performed without an inert gas atmosphere and with low catalyst loading. Investigations revealed that the presence of catalyst and PTC were essential for the catalysis reaction. The scope of aryl halide substrates was investigated by using the catalytic system under the optimized reaction conditions. It was also demonstrated that the catalytic system tolerated a variety of functionalized aryl halides in the reaction, including nitrile, nitro, acetyl, and ether groups. The new catalytic system was applied to a variety of imidazole derivatives to expand the scope of the methodology.
- Wang, Yi,Wu, Zhiqing,Wang, Lixia,Li, Zhengkai,Zhou, Xiangge
-
supporting information; experimental part
p. 8971 - 8974
(2010/04/05)
-
- Pyridine N-oxides as ligands in Cu-catalyzed Af-arylation of imidazoles in water
-
N-Arylation of imidazoles with aryl halides catalyzed by a combination of copper(II) sulfate and 1,2-bis(2-pyridyl)-ethane-N,N′-dioxide in water afforded up to 95% yield.
- Liang, Lei,Li, Zhengkai,Zhou, Xiangge
-
supporting information; experimental part
p. 3294 - 3297
(2009/11/30)
-
- Facile cuI-catalyzed arylation of azoles and amides using simple enaminones as efficient ligands
-
(E)-3-(Dimethylamino)-1-(2-hydroxyphenyl)prop-2-en-1-one was found to be an excellent ligand for copper-catalyzed N-arylation of azoles and amides with aryl halides under mild conditions. The reaction took place at 82 C in MeCN with broad functional-group compatibility. A combination of the ligand and CuI proved to be an efficient catalytic system to promote the coupling reactions of aryl halides with azoles and amides.
- Cheng, Cungui,Sun, Gonglei,Wan, Jieping,Sun, Cuirong
-
experimental part
p. 2663 - 2668
(2010/01/16)
-
- N-arylations of nitrogen-containing heterocycles with aryl and heteroaryl halides using a copper(I) oxide nanoparticle/1,10-phenanthroline catalytic system
-
A general procedure for solvent-free N-arylations of nitrogen-containing heterocycles, i.e. imidazoles, triazoles, and indoles, with aryl and heteroaryl halides catalyzed by copper(I) oxide (Cu2O) nanoparticles is demonstrated. Four types of Cu2O were evaluated: the bulky compound and its cubic, octahedral, and spherical nanoparticulate forms. The results show that Cu2O nanoparticles, in particular the cubic form, are highly efficient for the N-arylation reaction. In the presence of cubic Cu2O nanoparticles, 1,10-phenanthroline, and tetrabutylammonium fluoride, a variety of nitrogen-containing heterocycles smoothly underwent N-arylation with aryl and heteroaryl halides at 110-145 °C to give the corresponding products in moderate to excellent yields. It is noteworthy that the reaction is conducted under solvent-free conditions. The reaction mechanism is also discussed.
- Tang, Bo-Xiao,Guo, Sheng-Mei,Zhang, Man-Bo,Li, Jin-Heng
-
p. 1707 - 1716
(2008/12/22)
-
- Copper(I) oxide catalyzed N-arylation of azoles and amines with arylboronic acid at room temperature under base-free conditions
-
N-Arylation of azoles and amines with arylboronic acids was efficiently carried out with heterogeneous copper(I) oxide in methanol at room temperature under base-free conditions. The products N-arylazoles and N-arylamines were isolated in good to excellent yields. A variety of arylboronic acids and amines were converted to the corresponding N-arylazoles and N-arylamines, demonstrating the versatality of the reaction. Georg Thieme Verlag Stuttgart.
- Sreedhar, Bojja,Venkanna, Gopaladasu T.,Shiva Kumar, Kota Balaji,Balasubrahmanyam, Vura
-
p. 795 - 799
(2008/09/21)
-
- Solvent-free copper/iron co-catalyzed N-arylation reactions of nitrogen-containing heterocycles with trimethoxysilanes in air
-
A solvent-free copper/iron-catalyzed N-arylation of nitrogen-containing heterocycles with trimethoxysilanes method for the formation of C-N bonds has been developed. In the presence of Cu, FeCl3, TBAF, and air, a variety of nitrogen-containing heterocycles including imidazoles and triazoles were coupled with aryltrimethoxysilanes and vinyltrimethoxysilane to afford the corresponding products in moderate to excellent yields. It is noteworthy that the reaction is conducted under solvent-free and relatively low Cu/FeCl3 loadings conditions.
- Song, Ren-Jie,Deng, Chen-Liang,Xie, Ye-Xiang,Li, Jin-Heng
-
p. 7845 - 7848
(2008/03/11)
-
- Benzotriazole: an excellent ligand for Cu-catalyzed N-arylation of imidazoles with aryl and heteroaryl halides
-
Benzotriazole (BtH) is an efficient ligand for the Cu-catalyzed N-arylation of imidazoles with aryl and heteroaryl halides. A combination of CuI/BtH was found to be an efficient and inexpensive catalyst system to carry out the N-arylation of imidazoles affording the corresponding products in good to excellent yields.
- Verma, Akhilesh Kumar,Singh, Jaspal,Sankar, V. Kasi,Chaudhary, Ritu,Chandra, Ramesh
-
p. 4207 - 4210
(2008/02/05)
-
- Magnetic nanoparticle-supported proline as a recyclable and recoverable ligand for the CuI catalyzed arylation of nitrogen nucleophiles
-
Magnetic nanoparticle-supported proline ligand was prepared and used for the CuI catalyzed Ullmann-type coupling reactions of aryl/heteroaryl bromides with various nitrogen heterocycles to form the corresponding N-aryl products in good to excellent yields
- Chouhan, Gagan,Wang, Dashan,Alper, Howard
-
p. 4809 - 4811
(2008/09/17)
-
- Monodentate phosphines provide highly active catalysts for Pd-catalyzed C-N bond-forming reactions of heteroaromatic halides/amines and (H)N-heterocycles
-
(Chemical Equation Presented) A good alternative: Highly reactive catalysts based on palladium and dialkylbiarylphosphino ligands provide unprecedented reactivity and selectivity in C-N bond-forming processes. The bulky monophosphine catalyst system Pd/1 was effective for the reaction of aryl/heteroaryl halides bearing primary amides and 2-aminoheterocycles (see scheme; dba = dibenzylideneacetone, R = CONH2, NH2), thus showing that monodentate phosphines are viable alternatives to, and sometimes superior to, chelating ligands.
- Anderson, Kevin W.,Tundel, Rachel E.,Ikawa, Takashi,Altman, Ryan A.,Buchwald, Stephen L.
-
p. 6523 - 6527
(2007/10/03)
-
- A mild and efficient method for N-arylation of nitrogen heterocycles with aryl halides catalyzed by Cu(II)-NaY zeolite
-
A mild and efficient method for N-arylation of nitrogen-containing heterocycles with aryl halides to afford N-arylheterocycles in excellent yields using a Cu(II)-NaY catalyst in the presence of K2CO3 base is reported. Georg Thieme Verlag Stuttgart.
- Kantam, M. Lakshmi,Rao, B. Purna Chandra,Choudary,Reddy, R. Sudarshan
-
p. 2195 - 2198
(2007/10/03)
-
- An efficient base-free N-arylation of imidazoles and amines with arylboronic acids using copper-exchanged fluorapatite
-
(Chemical Equation Presented) N-Arylation of imidazoles and amines with arylboronic acids was accomplished with copper-exchanged fluorapatite (Cu-FAP) in methanol at room temperature. The products N-arylimidazoles and N-arylamines were isolated in good to excellent yields. A variety of arylboronic acids were converted to the corresponding N-arylimidazoles and N-arylamines, demonstrating the versatility of the reaction.
- Kantam, M. Lakshmi,Venkanna, Gopaldasu T.,Sridhar, Chidara,Sreedhar, Bojja,Choudary, Boyapati M.
-
p. 9522 - 9524
(2007/10/03)
-
- Ionic liquid-accelerated N-arylation of benzoazoles with diaryliodonium salts, an efficient method for the synthesis of N-aryl azoles
-
N-Arylation of benzoazoles with diaryliodonium salts can be performed in good yields in the room-temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4), which provides an efficient method for the synthesis of N-arylbenzoazoles. The ionic liquid can be recycled and reused.
- Wang, Feng-Yan,Chen, Zhen-Chu,Zheng, Qin-Guo
-
p. 206 - 207
(2007/10/03)
-