- A solvent-free manganese(II) -catalyzed Clauson-Kaas protocol for the synthesis of N-aryl pyrroles under microwave irradiation
-
The first manganese-catalyzed modified Clauson-Kaas reaction for N-substituted pyrrole synthesis using 2,5-dimethoxytetrahydrofuran with variously substituted aromatic amines has been developed (up to 89% yield). This interesting neat strategy is free from additives including co-catalysts, ligands, and acids. Relatively low cost, environmentally benign, and handy Mn(NO3)2·4H2O is employed as the catalyst under microwave conditions with a very short reaction time (20?min). The above qualities attest to the green nature of this reaction.
- Rohit, Kizhakkekuttu Radhakrishnan,Meera, Gopinadh,Anilkumar, Gopinathan
-
supporting information
p. 194 - 200
(2021/10/12)
-
- Synthesis of 1,3-Azaphospholes with Pyrrolo[1,2- a]quinoline Skeleton and Their Optical Applications
-
A facile synthesis of 1,3-azaphospholes with a pyrrolo[1,2-a]quinoline skeleton has been described. These new annulated 1,3-azaphospholes exhibit good photoelectric performance and can be used as the emitting dopant in organic light-emitting diodes (OLEDs) and dye for bioimaging.
- Wu, Di,Chen, Lingfeng,Ma, Shuangliang,Luo, Huiying,Cao, Jing,Chen, Runfeng,Duan, Zheng,Mathey, Francois
-
p. 4103 - 4106
(2018/07/15)
-
- Synthesis of pyrrolo[1,2-a] quinolines and ullazines by visible light mediated one- and twofold annulation of N-arylpyrroles with arylalkynes
-
1-(2-Bromophenyl)-1H-pyrrole and 1-(2,6-dibromophenyl)-1H-pyrrole react in the presence of catalytic amounts of rhodamine 6G (Rh-6G) and N,N-diisopropylethylamine (DIPEA) under blue light irradiation with aromatic alkynes and subsequently cyclize intramol
- Das, Amrita,Ghosh, Indrajit,K?nig, Burkhard
-
supporting information
p. 8695 - 8698
(2016/07/15)
-
- A novel and convenient method for the preparation of 5-(diphenylmethylene)-1H-pyrrol-2(5H)-ones; synthesis and mechanistic study
-
An efficient, regioselective synthesis has been developed for the preparation of 5-(diphenylmethylene)-1H-pyrrol-2(5H)-ones from readily available 1H-pyrroles by sequential dibromination and selective organometallic bromine/lithium exchange followed by reaction with benzophenone. Comparison of various N-substituents was shown to demonstrate the high tolerance of the transformation to functional groups. The structures of the new products were determined by spectroscopic methods and confirmed by single-crystal X-ray diffraction measurement. In addition, theoretical study of the reaction mechanism and selective functionalization of the endocyclic double bond were also presented.
- Faigl, Ferenc,Deák, Szilvia,Mucsi, Zoltán,Hergert, Tamás,Balázs, László,Sándor, Boros,Balázs, Barbara,Holczbauer, Tamás,Nyerges, Miklós,Mátrav?lgyi, Béla
-
p. 5444 - 5455
(2016/08/04)
-
- Steric vis-à-vis electronic influence of phosphines on biaryl motif: Ligand design for coupling reactions with Chloroarenes
-
In order to assess relative contribution of steric factors and electron-richness of phosphine ligands on biaryl-type scaffolds, a set of 1-aryl-pyrazole/pyrrole derived ligands L1-L6 featuring either aryldicyclohexylphosphino or aryldiphenylphosphino donor group was synthesized. A bidentate coordination mode of ligands L1 or L2 was evident from a representative crystal structure that implied a possible hemilabile participation to facilitate catalytic steps. With N-arylpyrroles (L3-L5), where the second nitrogen donor on the heterocycle is absent, coupling reactions of unactivated chloroarenes still proceeded with comparable efficiency. Thus, suitably endowed triarylphosphines were found to be as efficient as more expensive aryldialkylphosphine analogs in reactions with chloroarenes, extending the scope of ligand design.
- Saha, Debajyoti,Ghosh, Raju,Dutta, Ranjan,Mandal, Achintya Kumar,Sarkar, Amitabha
-
-
- Steric vis-??-vis electronic influence of phosphines on biaryl motif: Ligand design for coupling reactions with Chloroarenes
-
In order to assess relative contribution of steric factors and electron-richness of phosphine ligands on biaryl-type scaffolds, a set of 1-aryl-pyrazole/pyrrole derived ligands L1-L6 featuring either aryldicyclohexylphosphino or aryldiphenylphosphino donor group was synthesized. A bidentate coordination mode of ligands L1 or L2 was evident from a representative crystal structure that implied a possible hemilabile participation to facilitate catalytic steps. With N-arylpyrroles (L3-L5), where the second nitrogen donor on the heterocycle is absent, coupling reactions of unactivated chloroarenes still proceeded with comparable efficiency. Thus, suitably endowed triarylphosphines were found to be as efficient as more expensive aryldialkylphosphine analogs in reactions with chloroarenes, extending the scope of ligand design.
- Saha, Debajyoti,Ghosh, Raju,Dutta, Ranjan,Mandal, Achintya Kumar,Sarkar, Amitabha
-
-
- One-Pot Synthesis of Pyrrolo[1,2- a ]quinoxaline Derivatives via a Copper-Catalyzed Aerobic Oxidative Domino Reaction
-
A copper-catalyzed process for the synthesis of pyrrolo[1,2-a]quinoxalines from readily available α-amino acids and 1-(2-halophenyl)-1H-pyrroles is described. Different functional groups were well tolerated to give the corresponding products.
- Liu, Huanhuan,Duan, Tiantian,Zhang, Zeyuan,Xie, Caixia,Ma, Chen
-
supporting information
p. 2932 - 2935
(2015/06/30)
-
- L-(+)-Tartaric acid and choline chloride based deep eutectic solvent: An efficient and reusable medium for synthesis of N-substituted pyrroles via Clauson-Kaas reaction
-
l-(+)-Tartaric acid-choline chloride based deep eutectic solvent has been found to be an effective promoted medium for Clauson-Kaas reaction of aromatic amines and 2,5-dimethoxytetrahydrofuran. Structurally diverse N-substituted pyrroles were obtained in high to excellent yields under mild conditions. The deep eutectic solvent is inexpensive, non-toxic, reusable and biodegradable.
- Wang, Ping,Ma, Fei-Ping,Zhang, Zhan-Hui
-
p. 259 - 262
(2014/11/07)
-
- 2-(1-benzotriazolyl)pyridine: A robust bidentate ligand for the palladium-catalyzed C-C (Suzuki, Heck, Fujiwara-Moritani, Sonogashira), C-N and C-S coupling reactions
-
A new class of bidentate ligand, 1-(pyridine-2-yl)-1H-benzo[d][1,2,3] triazole has been designed and employed for the palladium-catalyzed C-C (Suzuki, Heck, Fujiwara-Moritani, and Sonogashira), C-N and C-S coupling reactions. The ligand was found to be inexpensive, thermally stable, easy to synthesize from easily accessible starting materials on a multigram scale, show simplicity in use, and robustness in application, making this ligand effective for different coupling reactions. Suitably, the donor ability of the N=N bond of the benzotriazole ring and lone pair of electrons on the N of the pyridine ring enhance the bidentate ability of the ligand.
- Verma, Akhilesh K.,Jha, Rajeev R.,Chaudhary, Ritu,Tiwari, Rakesh K.,Danodia, Abhinandan K.
-
p. 421 - 438
(2013/05/08)
-
- A recyclable magnetic nanoparticles supported antimony catalyst for the synthesis of N-substituted pyrroles in water
-
A new magnetic nanoparticle-supported antimony catalyst was prepared and evaluated as a recoverable catalyst for Clauson-Kaas reaction. The reaction proceeds efficiently in aqueous medium to give the corresponding N-substituted pyrroles in high yield. The immobilized catalyst could be easily recovered by magnetic separation and recycled for six times without significant loss of its catalytic activity.
- Ma, Fei-Ping,Li, Pei-He,Li, Bao-Le,Mo, Li-Ping,Liu, Ning,Kang, Hui-Jun,Liu, Ya-Nan,Zhang, Zhan-Hui
-
-
- Palladium-catalyzed sonogashira-coupling conjoined C-H activation: A regioselective tandem strategy to access indolo- and pyrrolo[1,2- a ]quinolines
-
An operationally simple approach for the regioselective tandem synthesis of indolo[1,2-a]quinolines 4a-v and pyrrolo[1,2-a]quinolines 5a-k from 1-(2-bromophenyl)-1H-indole/pyrrole/imidazole 1a-c, 2a,b by the palladium-catalyzed sequential C-C bond formation is described. The developed approach involves the palladium-catalyzed Sonogashira coupling followed by the intramolecular C-C bond formation via C-H activation, which leads to the formation of 6-endo-dig cyclized product. This synthetic methodology accommodates wide functional group variation on alkyne, which proves to be advantageous for the structural and biological activity assessments.
- Shukla, Satya Prakash,Tiwari, Rakesh K.,Verma, Akhilesh K.
-
p. 10382 - 10392
(2013/01/15)
-
- Palladium-catalyzed cyclocoupling of 2-halobiaryls with isocyanides via the cleavage of carbon-hydrogen bonds
-
(Figure Presented) To demonstrate the utility of isocyanides in catalytic C-H bond functionalization reactions, a palladium-catalyzed cyclocoupling reaction of 2-halobiaryls with isocyanides was developed. The reaction afforded an array of fluorenone imine derivatives via the cleavage of a C-H bond at the 2′-position of 2-halobiaryls. The use of 2,6-disubstituted phenyl isocyanide was crucial for this catalytic cyclocoupling reaction to proceed. The reaction was applicable to heterocyclic and vinylic substrates, allowing the construction of a wide range of ring system. The large kinetic isotope effect observed (kH/kD = 5.3) indicates that C-H bond activation was the turnover-limiting step in this catalysis.
- Tobisu, Mamoru,Imoto, Shinya,Ito, Sana,Chatani, Naoto
-
supporting information; body text
p. 4835 - 4840
(2010/10/04)
-
- Benzotriazole: an efficient ligand for the copper-catalyzed N-arylation of indoles
-
A general, efficient, and inexpensive method for the N-arylation of indoles using a catalytic system derived from CuI and benzotriazole is reported. Selective mono N-arylation of indoles with ortho-dihaloarenes has also been successfully achieved in good yields using this protocol.
- Verma, Akhilesh Kumar,Singh, Jaspal,Larock, Richard C.
-
scheme or table
p. 8434 - 8439
(2009/12/26)
-
- Highly practical "ligand-free-like" copper-catalyzed N-arylation of azoles in lower nitrile solvents
-
In lower nitrile solvents, the N-arylation of azoles with aryl halides was achieved efficiently in the presence of copper powder without any additional ligands. Thus, the first nitrile type of monodentate ligand-mediated, "ligand-free-like" copper-catalyzed N-arylation procedure was established.
- Zhu, Rui,Xing, Lixin,Wang, Xinyan,Cheng, Chuanjie,Su, Deyong,Hu, Yuefei
-
supporting information; experimental part
p. 1253 - 1257
(2009/06/18)
-
- Palladium-catalyzed annulation of aryl heterocycles with strained alkenes
-
An annulation reaction proceeding by the intermolecular addition of an arylpalladium(II) halide across a strained alkene, followed by an intramolecular C-H functionalization of a pendant heterocycle is described. A variety of polycyclic heterocycles have
- Hulcoop, David G.,Lautens, Mark
-
p. 1761 - 1764
(2008/02/02)
-
- Solvent and ligand effects on selective mono- and dilithiation of 1-(chlorophenyl)pyrroles and 1-(methoxyphenyl)pyrroles
-
Novel methods for site-selective lithiation of 1-(chlorophenyl)pyrroles and 1-(methoxyphenyl)pyrroles are described. Mono- or dilithiations are governed by change of both the temperature and the solvent from tetrahydrofuran to diethyl ether. Regioselectiv
- Fogassy, Katalin,Kovacs, Krisztina,Keseru, Gyoergy M.,Toke, Laszlo,Faigl, Ferenc
-
p. 1039 - 1043
(2007/10/03)
-
- Prostaglandin synthase inhibitors
-
This invention relates to ortho substituted phenyl compounds as inhibitors of prostaglandin synthase, to pharmaceutical compositions comprising such compounds and to methods of using such compounds as antiinflammatory and antipyretic agents. The class of compounds useful in this method of treatment is represented by Formula I below: STR1
- -
-
-