- TBHP/Cu(OAc)2 mediated oxidation of pyrazolines: A convenient method for the preparation of pyrazoles
-
An efficient and simple oxidative protocol has been developed for the preparation of pyrazoles from pyrazolines mediated by TBHP/Cu(OAc)2 at room temperature. The present protocol has been successfully applied for the preparation of various pyrazole compounds from heterocyclic pyrazolines.
- Kolla, Sai Teja,Somanaboina, Ramya,Bhimapaka, China Raju
-
p. 1425 - 1432
(2021/02/27)
-
- Ruthenium-catalyzed formation of pyrazoles or 3-hydroxynitriles from propargyl alcohols and hydrazines
-
Functionalized pyrazoles are generated from secondary propragyl alcohols and hydrazines in a ruthenium-catalyzed cascade process, consisting of redox isomerization, Michael addition, cyclocondensation and dehydrogenation steps. The same bifunctional catalyst mediates the conversion of tertiary propargyl alcohols with hydrazine to 3-hydroxynitriles via anti-Markovnikov hydroamination followed by elimination of ammonia.
- Kaufmann, Julia,J?ckel, Elisabeth,Haak, Edgar
-
supporting information
p. 91 - 101
(2019/07/09)
-
- Palladium-Catalyzed Deformylation Reactions with Detailed Experimental and in Silico Mechanistic Studies
-
A facile, efficient, and general deformylation reaction with a wide-ranging functional group compatibility has been developed with palladium acetate as a precatalyst under exogenous ligand-free conditions. The mechanistic details of the palladium-catalyzed deformylation reaction have been outlined on the basis of a combination of experimental and computational studies. The heterogeneous pathway is predominant for the deformylation, and homogeneous catalysis occurs to a lesser extent. This ligand-free catalytic cycle is proposed to undergo oxidative addition, migratory extrusion, and reductive elimination as the key steps. Kinetic studies reveal a first-order rate dependency with respect to the aldehyde. Furthermore, kinetic isotope effects, competition experiments, and Hammett studies suggest that the migratory extrusion step is the rate-determining step. For the homogeneous pathway, the experimental findings are also supported by DFT studies.
- Modak, Atanu,Rana, Sujoy,Phukan, Ashwini K.,Maiti, Debabrata
-
supporting information
p. 4168 - 4174
(2017/08/07)
-
- A 2, 4 - dimethyl thiazole-based acrylonitrile compounds and use thereof (by machine translation)
-
The invention discloses a novel structure of the 2, 4 - dimethyl thiazole-based acrylonitrile compound or a stereoisomer thereof, a compound structure such as shown in formula I: In the formula: C R is selected from1 - C6 Alkyl, C1 - C6 Haloalkyl, C3 - C8 Cycloalkyl or C1 - C6 Alkoxy; Q is selected from the following group: R1 Is selected from H, halogen, methyl or trifluoromethyl; R2 Is selected from halogen; R3 , R4 Are independently selected from H, halogen, methyl or trifluoromethyl; or a stereoisomer thereof. The formula I compounds have excellent insecticidal, acaricidal activity, can be used for the pest, mites. (by machine translation)
- -
-
Paragraph 0136; 0137; 0138; 0139
(2017/08/02)
-
- A 2, 4 - dimethyl [...] acrylonitrile compounds and use thereof
-
The invention discloses a 2,4-dimethylthiazole acrylonitrile compound or a stereoisomer thereof with a novel structure. The structure of the compound is shown in the general formal (I) in the specification, wherein R is selected from alkyl of C1-C6, halogenated alkyl of C1-C6, naphthene of C3-C8 or alkoxy of C1-C6; Q is selected from the group as shown in the specification; R1 is selected from H, halogen, methyl or trifluoromethyl; R2 is selected from H, halogen, methyl or trifluoromethyl; or the stereoisomer of the compound is selected. The compound in the general formula I has excellent insect and mite killing activity, and can be used for preventing and controlling insects and mites.
- -
-
Paragraph 0138; 0139; 0140
(2017/12/27)
-
- Pyrazolyl acrylonitrile compound and use thereof
-
The invention discloses a pyrazolyl acrylonitrile compound or a stereisomer thereof with a novel structure. The structure of the compound is shown as the general formula I in the specification, wherein R is one of alkyl of C1-C6, halogenated alkyl of C1-C6, cycloalkyl of C3-C8, alkoxy of C1-C6 and phenyl; hydrogen on a benzene ring can be further substituted by the following groups: halogen, cyan, nitro, methyl or halogenated methyl; R2 is one of hydrogen, halogen, cyan and methyl; R3 is alkyl of C1-C6; R4 and R5 are respectively one of hydrogen, methyl, halogen, cyan and nitro. The compound in the general formula I has excellent insect and mite killing activity, and can be used for preventing and controlling insects and mites.
- -
-
Paragraph 0123; 0124; 0125
(2016/10/08)
-
- Copper-catalyzed C–N cross-coupling of arylboronic acids with N-acylpyrazoles
-
A copper-catalyzed C–N bond forming reaction of arylboronic acids and N-acylpyrazoles was developed. This procedure used N-acetyl protected pyrazoles as starting material instead of free pyrazoles (NH). The reaction worked under neutral conditions and did not require any base or ligand. The reaction showed good functional group tolerance.
- Zhang, Jin,Jia, Run-Ping,Wang, Dong-Hui
-
supporting information
p. 3604 - 3607
(2016/07/21)
-
- 2- [...] azoly acrylonitrile compound and use thereof
-
The invention discloses a 2-chloro thiazolyl acrylonitrile compound or a stereisomer thereof with a novel structure. The structure of the compound is shown as the general formula I in the specification, wherein R is one of alkyl of C1-C6, halogenated alkyl of C1-C6, cycloalkyl of C3-C8 and alkoxy of C1-C6; Q is selected from the group shown as the specification; R1 is one of H, halogen, methyl and trifluoromethyl; R2 is one of H and halogen. The compound in the general formula I has excellent insect and mite killing activity, and can be used for preventing and controlling insects and mites.
- -
-
Paragraph 0130-0132
(2016/10/08)
-
- Phenyl pyrazolyl acrylonitrile compound and use thereof
-
The present invention discloses a novel structure phenyl pyrazolyl acrylonitrile compound or a stereoisomer thereof, wherein the structure of the compound is represented by a general formula I, R1 is selected from C1-C6 alkyl, halogenated C1-C6 alkyl, C3-C8 cycloalkyl, C1-C6 alkoxy and phenyl, hydrogen on the benzene ring can be further substituted by the following substituting groups such as halogen, cyano, nitro, methyl and halomethyl, and R2 is selected from chlorine, trifluoromethyl and nitro. The compound represented by the general formula I has excellent insect disinfestation and mite killing activity, and can be used for prevention and control of pests and mites.
- -
-
Paragraph 0071-0073
(2016/10/10)
-
- Thiazole base pyrazolyl acrylonitrile compounds and use thereof
-
The invention discloses a thiazolyl pyrazolyl acrylonitrile compound or a stereisomer thereof with a novel structure. The structure of the compound is shown as the general formal in the specification, wherein R is one of alkyl of C1-C6, halogenated alkyl of C1-C6, cycloalkyl of C3-C8, alkoxy of C1-C6 and phenyl; hydrogen on a benzene ring can be further substituted by the following groups: halogen, cyano groups, nitro, methyl or halogenated methyl; X is one of chlorine, bromine or iodine. The compound in the general formula I has excellent insect and mite killing activity, and can be used for preventing and controlling insects and mites.
- -
-
Paragraph 0061; 0062; 0063
(2017/01/17)
-
- Copper-catalyzed arylation of nitrogen heterocycles from anilines under ligand-free conditions
-
The arylation of pyrazole and derivatives can be achieved by coupling arenediazonium species (formed in situ from anilines) by using a catalytic system that employs low-toxicity and inexpensive copper metal under very mild and ligand-free conditions (T = 20 ° C). From other nitrogen heterocycles, the presence of an additive (NBu4I) significantly improves the efficiency of the catalytic system. These results represent the first examples of C-N bond formation from arenediazonium species.
- Toummini, Dounia,Tlili, Anis,Bergs, Julien,Ouazzani, Fouad,Taillefer, Marc
-
supporting information
p. 14619 - 14623
(2015/01/09)
-
- An efficient dehydroxymethylation reaction by a palladium catalyst
-
A general method for selective dehydroxymethylation has been discovered by using widely available Pd(OAc)2. The present study offers a new synthetic strategy for the regioselective functionalization by employing the steric, electronic and coordinating nature of the hydroxymethyl (-CH 2OH) group temporarily.
- Modak, Atanu,Naveen, Togati,Maiti, Debabrata
-
p. 252 - 254
(2013/02/22)
-
- Nickel-catalyzed hydrogenolysis of unactivated carbon-cyano bonds
-
Selective hydrogenolysis of C-CN bonds can allow chemists to take advantage of ortho-directing ability, α-C-H acidity and electron withdrawing ability of the cyano group for synthetic manipulations. We have discovered hydrogenolysis of aryl and aliphatic cyanides under just 1 bar of hydrogen by using a nickel catalyst. This protocol was applied in the aryl cyanide directed functionalization reaction and α-substitution of benzyl cyanides.
- Patra, Tuhin,Agasti, Soumitra,Modak, Atanu,Maiti, Debabrata
-
supporting information
p. 8362 - 8364
(2013/09/23)
-
- A general and efficient aldehyde decarbonylation reaction by using a palladium catalyst
-
A facile decarbonylation reaction of aldehydes has been developed by employing Pd(OAc)2. A wide variety of substrates are decarbonylated, without using any exogenous ligand for palladium as well as CO-scavenger.
- Modak, Atanu,Deb, Arghya,Patra, Tuhin,Rana, Sujoy,Maity, Soham,Maiti, Debabrata
-
supporting information; experimental part
p. 4253 - 4255
(2012/05/04)
-
- Microwave-assisted palladium mediated decarbonylation reaction: Synthesis of eulatachromene
-
Microwave-assisted decarbonylation reactions were investigated using a palladium catalyst. A large number of aldehydes can be decarbonylated efficiently with lower catalyst loadings and under shorter reaction times compared to conventional heating. A successful decarbonylation led to the synthesis of natural product eulatachromene in three steps starting from easily available materials.
- Akanksha,Maiti, Debabrata
-
experimental part
p. 2314 - 2320
(2012/09/21)
-
- METHOD FOR RAPIDLY METHYLATING HETEROAROMATIC ARENE AND METHOD FOR PRODUCING TRACER FOR USE IN PET
-
Provided is a method whereby a heteroaromatic ring aryl can be very rapidly methylated at a high yield. In an N-alkyl-2-pyrrolidinone, a heteroaromatic ring aryltrialkylstannan is cross-coupled with methyl iodide in the presence of a palladium complex, a phosphine ligand, a cuprous halide, a carbonic acid salt and/or an alkali metal fluoride to thereby rapidly methylate the heteroaromatic ring aryl. (Formula shows a case wherein the heteroaromatic ring aryl is a pyridyl group.)
- -
-
Page/Page column 5-6
(2011/11/06)
-
- PYRAZOLE DERIVATIVES AS S1P1 AGONISTS
-
The present invention relates to a compound of formula (I), to the process for preparing such compounds and to their use in the treatment of a pathological condition or disease susceptible to amelioration by sphingosine-1-phosphate receptors (S1P1) agonists.
- -
-
Page/Page column 81
(2011/12/04)
-
- New pyrazole derivatives
-
The present invention relates to a compound of formula (I), to the process for preparing such compounds and to their use in the treatment of a pathological condition or disease susceptible to amelioration by sphingosine-1-phosphate receptors (S1P1) agonists.
- -
-
Paragraph 0391; 0392
(2013/03/26)
-
- A manganese/copper bimetallic catalyst for C-N coupling reactions under mild conditions in water
-
An efficient and convenient bimetallic MnF2/CuI catalyst in combination with trans-1,2-diaminocyclohexane has been developed for the cross-coupling of nitrogen heterocycles with aryl halides in water at moderate temperature. A variety of nitrogen nucleophiles including pyrazole, 7-azaindole, indazole, indole, pyrrole and imidazole afforded the corresponding products in moderate to good yields (up to 94%) under the described arylation conditions.
- Teo, Yong-Chua,Yong, Fui-Fong,Lim, Gina Shiyun
-
supporting information; experimental part
p. 7171 - 7174
(2012/01/05)
-
- Dimethyl sulfoxide/potassium hydroxide: A superbase for the transition metal-free preparation of cross-coupling products
-
Potassium hydroxide (KOH) in dimethyl sulfoxide (DMSO) forms a superbasic medium that allows one to access cross-coupling products from reactions between aryl halides with various sulfur-, oxygen- and nitrogen-based nucleophiles under transition metal-free conditions. Copyright
- Yuan, Yu,Thome, Isabelle,Kim, Seok Hwan,Chen, Duanteng,Beyer, Astrid,Bonnamour, Julien,Zuidema, Erik,Chang, Sukbok,Bolm, Carsten
-
experimental part
p. 2892 - 2898
(2011/01/05)
-
- Pd0-mediated rapid coupling between methyl iodide and heteroarylstannanes: an efficient and general method for the incorporation of a positron-emitting11C radionuclide into heteroaromatic frameworks
-
The Pd0-mediated rapid trapping of methyl iodide with an excess amount of a heteroaryl-substituted tributylstannane has been investigated with the aim of incorporating a shortlived 11C-labelled methyl group into the heteroaromatic carbon frameworks of important organic compounds, such as drugs with various heteroaromatic structures, in order to execute a positron emission tomography (PET) study of vital systems. The reaction was first performed by using our previously developed CH3I/stannane/[Pd 2(dba)3]/ P(o-CH3C6H 4)3/CuCl/K2CO3 (1:40:0.5:2:2:2) system in DMF at 60°C for 5 min (conditions A), however, the reaction gave low yields for various heteroaromatic compounds. Increasing the amount of phosphine ligand (condi tions B) led to a significant improvement in the yield, but the conditions were still not suitable for a range of basic heteroaromatic structures. Use of the CuBr/CsF system (conditions C) also provided a result similar to that obtained under conditions B with an increased amount of the phosphine. Thus, pyridine and related heteroaromatic compounds remained less reactive substrates. The problem was overcome by replacing the DMF solvent with N-methyl-2-pyrolidinone (NMP). The reaction in NMP at 60-100°C for 5 min using a CH3I/stannane/[Pd2-(dba)3]/P(o-CH 3C6H4)3/CuBr/CsF (1:40:0.5:16:2:5) combination (conditions D) gave the methylated products in yields of more than 80% (based on the reaction of CH3I) for all of the heteroaromatic compounds listed in this study. Thus, the combined use of NMP and an increased amount of phosphine is important for promoting the reaction efficiently. The use of this general approach to rapid methylation has been well demonstrated by the synthesis of the PET tracers 2- and 3-[11C]methylpyridines by using [Pd2(dba)3]/P(o-CH3C6H 4)3/CuBr/CsF (1:16:2:5) in NMP at 60°C for 5 min, which gives the desired products in HPLC analytical yields of 88 and 91%, respectively.
- Suzuki, Masaaki,Sumi, Kengo,Koyama, Hiroko,Siqin,Hosoya, Takamitsu,Takashima-Hirano, Misato,Doi, Hisashi
-
experimental part
p. 12489 - 12495
(2010/06/11)
-
- Manganese-catalyzed cross-coupling reactions of nitrogen nucleophiles with aryl halides in water
-
A facile and convenient strategy for the assembly of N-arylated heterocycles has been demonstrated using a MnCl2·4H 2O/trans-1,2-diaminocyclohexane catalyst and K3PO 4 as the base in water.
- Teo, Yong-Chua,Yong, Fui-Fong,Poh, Chai-Yun,Yan, Yaw-Kai,Chua, Guan-Leong
-
supporting information; experimental part
p. 6258 - 6260
(2010/02/16)
-
- Efficient cross-coupling reactions of nitrogen nucleophiles with aryl halides in water
-
A facile and practical strategy has been developed for the N-arylation of nitrogen nucleophiles with aryl halides catalyzed by a combination of iron(III) chloride [FeCl3] and dimethylethylenediamine (dmeda) in water. A variety of nitrogen nucleophiles including pyrazole, indole, 7-azaindole and benzamide afforded the N-arylated products in the presence of the catalytic system (in up to 88% yield).
- Teo, Yong-Chua
-
supporting information; experimental part
p. 720 - 724
(2009/11/30)
-
- Distinguishing features of reactions of 2-chloro- and 2,2-dichloro(bromo) vinyl ketones with alkyl- and arylhydrazines
-
2-Chlorovinyl alkyl ketones react with alkylhydrazines to give mixtures of 1-R-3-R′- and 1-R-5-R′-pyrazoles: The 1-R-3-R′-pyrazoles form through the heterocyclization of 2-chlorovinyl ketone alkylhydrazones whereas in the heterocyclization into 1-R-5-R′-pyrazoles N1-alkyl-N 2-(2-acylvinyl)hydrazines are involved. The regiospecific heterocyclization of 2-chloro-and 2,2-dichlorovinyl ketones with arylhydrazines and also of 2,2-dichloro(bromo)vinyl trifluoromethyl ketones with C alkylhydrazines into pyrazoles and 5-chloro(bromo)-pyrazoles proceeds through a stage of haloenones hydrazones formation. The study of the structure of the obtained 1-alkyl-3(5)-alkylpyrazoles by means of two-dimenaional 1H and 13C NMR spectroscopy and GC-MS method made it possible to assign the proton and carbon signals of isomeric pyrazoles and to establish the diagnostic ions for the pair of 1,3-and 1,5-isomers.
- Bozhenkov,Savosik,Larina,Klyba,Zhanchipova,Mirskova,Levkovskaya
-
experimental part
p. 1014 - 1023
(2009/07/05)
-
- Simple copper salt-catalyzed N-arylation of nitrogen-containing heterocycles with aryl and heteroaryl halides
-
(Chemical Equation Presented) Relatively mild and highly efficient CuI-catalyzed N-arylation procedures for nitrogen-containing heterocycles (e.g., imidazoles, benzimidazoles, pyrroles, pyrazoles, indoles, triazoles, etc.) with aryl and heteroaryl halides have been developed. The protocols can be performed easily and tolerate a number of functional groups, such as ester, nitrile, nitro, ketone, free hydroxyl, and free primary amine on the aryl halide.
- Zhu, Liangbo,Guo, Peng,Li, Gaocan,Lan, Jingbo,Xie, Rugang,You, Jingsong
-
p. 8535 - 8538
(2008/03/11)
-
- Regioselective synthesis of 1-aryl-3,4-substituted/annulated-5-(methylthio) pyrazoles and 1-aryl-3-(methylthio)-4,5-substituted/annulated pyrazoles
-
Highly efficient and regioselective synthesis of 1-aryl-3,4-substituted/ annulated-5-(methylthio)-pyrazoles and 1-aryl-3-(methylthio)-4,5-substituted/ annulated pyrazoles has been reported via cyclocondensation of arylhydrazines with either α-oxoketene dithioacetals or β-oxodithioesters.
- Peruncheralathan,Khan,Ila,Junjappa
-
p. 10030 - 10035
(2007/10/03)
-
- Mild conditions for copper-catalysed N-arylation of pyrazoles
-
Copper-catalysed N-arylation of pyrazoles with aryl or heteroaryl bromides or iodides, which can include functional substituents, was performed under the mildest conditions yet described, with excellent yields and selectivity, by the use as catalyst of a combination of cuprous oxide with a set of inexpensive, chelating oxime-type ligands not previously known to promote such reactions. Other original bi-, tri- or tetradentate ligands providing nitrogen and/or oxygen as chelating atoms were also successfully tested in this type of arylation. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
- Cristau, Henri-Jean,Cellier, Pascal P.,Spindler, Jean-Francis,Taillefer, Marc
-
p. 695 - 709
(2007/10/03)
-
- Hypervalent iodine in synthesis 57 : An efficient method for the synthesis of N-arylimidazoles by the cobalt-catalysed coupling of diaryliodonium salts with imidazoles
-
Cobalt-catalysed N-arylation of imidazole with diaryliodonium salt can be accomplished using Co(OAC)2 as a catalyst and K2CO3 as a base in DMF at 80 °C in high yields.
- Wang,Chen
-
p. 367 - 369
(2007/10/03)
-
- Phenylselenenyl sulfate induced cyclization of allylhydrazines. Synthesis of pyrazole derivatives
-
Allylhydrazines react with phenylselenenyl sulfate, produced by diphenyl diselenide and ammonium persulfate in the presence of trifluoromethanesulfonic acid, to afford phenylseleno substituted pyrazolidines. Under the reaction conditions employed, these suffer dehydrogenation and oxidative deselenenylation to eventually give pyrazole derivatives.
- Tieco, Marcello,Testaferri, Lorenzo,Marini, Francesca,Bagnoli, Luana,Santi, Claudio,Temperini, Andrea
-
p. 4441 - 4446
(2007/10/03)
-