Synthesis of functionalized 4-phenyl-pyridines via electrochemically prepared organozinc reagents
作者:Erwan Le Gall、Corinne Gosmini、Jean-Yves Nédélec、Jacques Périchon
DOI:10.1016/s0040-4020(01)00015-1
日期:2001.3
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 organozincreagents 1 and their coupling with pyridinium salts. Intermediate 1,4-dihydropyridines are oxidized using mild conditions to provide functionalized 4-phenyl-pyridines in moderate to high overall yields.
Enantioselective Synthesis of Chiral Piperidines via the Stepwise Dearomatization/Borylation of Pyridines
作者:Koji Kubota、Yuta Watanabe、Keiichi Hayama、Hajime Ito
DOI:10.1021/jacs.6b01375
日期:2016.4.6
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
[2,2′-Bipyridin]-6(1<i>H</i>)-one, a Truly Cooperating Ligand in the Palladium-Mediated C–H Activation Step: Experimental Evidence in the Direct C-3 Arylation of Pyridine
作者:Vanesa Salamanca、Alberto Toledo、Ana C. Albéniz
DOI:10.1021/jacs.8b10680
日期:2018.12.26
ligand [2,2'-bipyridin]-6(1 H)-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
Photoarylation of Pyridines Using Aryldiazonium Salts and Visible Light: An EDA Approach
作者:Aloisio de A. Bartolomeu、Rodrigo C. Silva、Timothy J. Brocksom、Timothy Noël、Kleber T. de Oliveira
DOI:10.1021/acs.joc.9b01879
日期:2019.8.16
A metal-free methodology for the photoarylation of pyridines, in water, is described giving 2 and 4-arylated-pyridines in yields up to 96%. 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
Yttrium‐Catalyzed
<i>ortho</i>
‐Selective C−H Borylation of Pyridines with Pinacolborane
作者:Yuncong Luo、Shengjie Jiang、Xin Xu
DOI:10.1002/anie.202117750
日期:2022.5.16
The ortho-selective C−Hborylation of a wide range of pyridines using pinacolborane was achieved through yttrium catalysis. Notably, the possible hydroboration side reaction was effectively suppressed by using the proper ligand/metal combination. The resultant 2-pyridyl boronates were subjected to further transformations such as a Suzuki–Miyaura coupling or the Chan–Lam amination.