5957-98-2Relevant academic research and scientific papers
Photoarylation of Pyridines Using Aryldiazonium Salts and Visible Light: An EDA Approach
Bartolomeu, Aloisio De A.,Brocksom, Timothy J.,De Oliveira, Kleber T.,No?l, Timothy,Silva, Rodrigo C.
, (2019/08/26)
A metal-free methodology for the photoarylation of pyridines, in water, is described giving 2 and 4-arylated-pyridines in yields up to 96percent. The scope of the aryldiazonium salts is presented showing important results depending on the nature and position of the substituent group in the diazonium salt, that is, electron-donating or electron-withdrawing in the ortho, meta, or para positions. Further heteroaromatics were also successfully photoarylated. Mechanistic studies and comparison between our methodology and similar metal-catalyzed procedures are presented, suggesting the occurrence of a visible-light EDA complex which generates the aryl radical with no need for an additional photocatalyst.
[2,2′-bipyridin]-6(1 H)-one, a Truly Cooperating Ligand in the Palladium-Mediated C-H Activation Step: Experimental Evidence in the Direct C-3 Arylation of Pyridine
Salamanca, Vanesa,Toledo, Alberto,Albéniz, Ana C.
supporting information, p. 17851 - 17856 (2019/01/04)
The ligand [2,2′-bipyridin]-6(1H)-one (bipy-6-OH) has a strong accelerating effect on the Pd-catalyzed direct arylation of pyridine or arenes. The isolation of relevant intermediates and the study of their decomposition unequivocally show that the deprotonated coordinated ligand acts as a base and assists the cleavage of the C-H bond. Mechanistic work indicates that the direct arylation of pyridine with this ligand occurs through a Pd(0)/Pd(II) cycle. Because of this dual ligand-intramolecular base role, there is no need for an available coordination site on the metal for an external base, a difficulty encountered when chelating ligands are used in coupling reactions that involve a C-H cleavage step.
Enantioselective Synthesis of Chiral Piperidines via the Stepwise Dearomatization/Borylation of Pyridines
Kubota, Koji,Watanabe, Yuta,Hayama, Keiichi,Ito, Hajime
supporting information, p. 4338 - 4341 (2016/05/09)
We have developed a novel approach for the synthesis of enantioenriched 3-boryl-tetrahydropyridines via the Cu(I)-catalyzed regio-, diastereo-, and enantioselective protoborylation of 1,2-dihydropyridines, which were obtained by the partial reduction of the pyridine derivatives. This dearomatization/enantioselective borylation stepwise strategy provides facile access to chiral piperidines together with the stereospecific transformation of a stereogenic C-B bond from readily available starting materials. Furthermore, the utility of this method is demonstrated for the concise synthesis of the antidepressant drug (-)-paroxetine. A theoretical study of the reaction mechanism is also described.
Selenium dioxide-mediated methoxyhydroxylation of cyclic arylolefin
Chang, Meng-Yang,Lin, Chung-Han,Chen, Yeh-Long
scheme or table, p. 1430 - 1433 (2010/05/03)
Selenium dioxide-mediated methoxyhydroxylation of cyclic arylolefin with the modest yields is described. This facile strategy was also used to synthesize several 4-arylpyridines, 3-hydroxy-4-arylpyridines, and 3,4-diarylpyridines. Crown Copyright
Synthesis of 4-Aryl-2-aminopyridine derivatives and related compounds
Pavlovic, Vladimir,Petkovic, Milos,Popovic, Stanimir,Savic, Vladimir
experimental part, p. 4249 - 4263 (2010/01/15)
A short, efficient, and high-yielding synthesis of 4-aryl-2-aminopyridine derivatives has been developed. The route employs two palladium-catalyzed processes, the Suzuki reaction and the Buchwald-Hartwig amination, as the key steps. The same approach has
Vesicular monoamine transporter substrate/inhibitor activity of MPTP/MPP+ derivatives: A structure-activity study
Wimalasena, D. Shyamali,Perera, Rohan P.,Heyen, Bruce J.,Balasooriya, Inoka S.,Wimalasena, Kandatege
, p. 760 - 768 (2008/09/19)
The active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), N-methyl-4-phenylpyridinium (MPP+), selectively destroys the dopaminergic neurons and induces the symptoms of Parkinson's disease. Inhibition of mitochondrial complex
Synthesis of functionalized 4-phenyl-pyridines via electrochemically prepared organozinc reagents
Gall, Erwan Le,Gosmini, Corinne,Nédélec, Jean-Yves,Périchon, Jacques
, p. 1923 - 1927 (2007/10/03)
The efficient and convenient synthesis of various functionalized 4-phenyl-pyridines 2 is described. The key step of the procedure is the electrochemical formation of aromatic organozinc reagents 1 and their coupling with pyridinium salts. Intermediate 1,4
