نتایج جستجو برای: pyridines

تعداد نتایج: 6741  

Journal: :Chemical communications 2012
Jie-Ping Wan Charles C J Loh Fangfang Pan Dieter Enders

The asymmetric synthesis of tetrahydropyridin-2-ols from enals and enaminones is described. The organocatalytic domino reaction involves a Michael addition-hemiaminalization sequence using the Jørgensen-Hayashi catalyst. Dehydration or oxidation leads to the corresponding 1,4-dihydro-pyridines or 3,4-dihydropyridin-2-ones in a one-pot fashion.

Journal: :Chemical communications 2010
Hans Andersson Thomas Sainte-Luce Banchelin Sajal Das Roger Olsson Fredrik Almqvist

Addition of Grignard reagents to pyridine N-oxides in THF at low temperature (-78 to -20 degrees C) and treatment with TFAA provides an efficient general procedure for synthesis of substituted pyridines. The method is compatible with a range of functional groups such as esters, halogens and nitriles.

Journal: :The Journal of organic chemistry 2007
Aitor Landa Bo Richter Rasmus Lyng Johansen Anna Minkkilä Karl Anker Jørgensen

A general catalytic oxo-hetero-Diels-Alder reaction for pro-chiral aldehyde and ketone N-oxy-pyridines is presented. The catalytic and asymmetric oxo-hetero-Diels-Alder reaction of electron-rich dienes with N-oxy-pyridine-2-carbaldehyde and ketone derivatives, catalyzed by chiral copper(II)-bisoxazoline complexes, gives optically active six-membered oxygen heterocycles in moderate to good yield...

Journal: :Chemical communications 2012
P Mahesh Kumar K Siva Kumar Pradeep Kumar Mohakhud K Mukkanti R Kapavarapu Kishore V L Parsa Manojit Pal

A conceptually new three-component reaction was developed to construct a six-membered fused N-heterocyclic ring affording (pyrazolo)pyrimidines/pyridines as potential inhibitors of PDE4. The reaction is catalyzed by triflic acid in acetic acid in the presence of aerial oxygen.

Journal: :Chemical communications 2011
Todd K Hyster Tomislav Rovis

The synthesis of pyridines from readily available α,β-unsaturated oximes and alkynes under mild conditions and low temperatures using Rh(III) catalysis has been developed. It was found that the use of sterically different ligands allows for complementary selectivities to be achieved.

2012
Wafa Gati Mohamed M Rammah Mohamed B Rammah Gwilherm Evano

We have developed a general synthesis of polysubstituted 1,4-dihydropyridines and pyridines based on a highly regioselective lithiation/6-endo-dig intramolecular carbolithiation from readily available N-allyl-ynamides. This reaction, which has been successfully applied to the formal synthesis of the anti-dyskinesia agent sarizotan, further extends the use of ynamides in organic synthesis and fu...

Journal: :Organic & biomolecular chemistry 2013
Lin Ling Jingqing Chen Jiahui Song Yuhai Zhang Xinqian Li Lijuan Song Feng Shi Yuxue Li Chunrui Wu

A Cu-mediated preparation of 2-substitiuted pyrazolo[1,5-a]pyridines from N-benzoylpyridinium imides and terminal alkynes is described using stoichiometric Cu(OAc)2 as both the mediator and the oxidant. Extensive DFT calculations suggest a Cu(III) intermediate via disproportionation of Cu(II).

Journal: :Chemical communications 2011
Jean-Pierre Djukic Wissam Iali Michel Pfeffer Xavier-Frédéric Le Goff

The reaction of chiral chlorido-iridacyclic 2-(4-N,N-dimethylaminophenyl)pyridines with solvato-type [Cp*M(S)(3)](q+) (M = Ru, S = MeCN, q = 1; M = Ir, S = MeC(O)Me, q = 2) complexes produces new cationic racemic planar chiral iridacycles in an efficient and diastereospecific way.

Journal: :Journal of the American Chemical Society 2015
Nathaniel T Kadunce Sarah E Reisman

A Ni-catalyzed asymmetric reductive cross-coupling of heteroaryl iodides and α-chloronitriles has been developed. This method furnishes enantioenriched α,α-disubstituted nitriles from simple organohalide building blocks. The reaction tolerates a variety of heterocyclic coupling partners, including pyridines, pyrimidines, quinolines, thiophenes, and piperidines. The reaction proceeds under mild ...

Journal: :Dalton transactions 2017
Ryota Okuno Minayo Yamaguchi Hideki Fujiwara

We report the first preparation of a symmetric tetrathiafulvalene (TTF)-pyridyl thiolato zinc(ii) complex in which two TTF parts connect to the central zinc atom through pyridines and thiolates. We also discuss the crystal structure analysis and physical properties of the complex, especially photocurrent generations measured on its thin-film sample and single crystal.

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