39795-58-9Relevant articles and documents
Quantitative Determination of the Electronic Effects of Pyridyl Groups
Shkurko, O. P.,Baram, S. G.,Mamaev, V. P.
, p. 60 - 65 (1983)
The series of ? constants of 2-, 3-, and 4-pyridyl groups was calculated on the basis of data from the 1H, 13C, and 19F NMR spectra of isomeric aminophenyl-, phenyl-, and fluorophenylpyridines.The literature ? constants and the values found in the research were analyzed.
Sequential Ring-Opening and Ring-Closing Reactions for Converting para-Substituted Pyridines into meta-Substituted Anilines
Morofuji, Tatsuya,Inagawa, Kota,Kano, Naokazu
, p. 6126 - 6130 (2021)
Herein we report a method for converting para-substituted pyridine rings into meta-dialkylamino-substituted benzene rings through sequential ring-opening and ring-closing reactions. The nitrogen atom in the pyridine rings was replaced with a methine group, and a dialkylamino substituent was introduced onto the original unsubstituted carbon atom in the pyridine rings. This process can be formally regarded as a hybrid of the skeletal editing and C-H amination of pyridine rings.
Mechanistic Studies of the Palladium-Catalyzed Desulfinative Cross-Coupling of Aryl Bromides and (Hetero)Aryl Sulfinate Salts
Davis, Christopher J.,De Gombert, Antoine,McKay, Alasdair I.,Wheelhouse, Katherine M.,Willis, Michael C.
, (2020/02/25)
Pyridine and related heterocyclic sulfinates have recently emerged as effective nucleophilic coupling partners in palladium-catalyzed cross-coupling reactions with (hetero)aryl halides. These sulfinate reagents are straightforward to prepare, stable to storage and coupling reaction conditions, and deliver efficient reactions, thus offering many advantages, compared to the corresponding boron-derived reagents. Despite the success of these reactions, there are only scant details of the reaction mechanism. In this study, we use structural and kinetic analysis to investigate the mechanism of these important coupling reactions in detail. We compare a pyridine-2-sulfinate with a carbocyclic sulfinate and establish different catalyst resting states, and turnover limiting steps, for the two classes of reagent. For the carbocyclic sulfinate, the aryl bromide oxidative addition complex is the resting state intermediate, and transmetalation is turnover-limiting. In contrast, for the pyridine sulfinate, a chelated Pd(II) sulfinate complex formed post-transmetalation is the resting-state intermediate, and loss of SO2 from this complex is turnover-limiting. We also investigated the role of the basic additive potassium carbonate, the use of which is crucial for efficient reactions, and deduced a dual function in which carbonate is responsible for the removal of free sulfur dioxide from the reaction medium, and the potassium cation plays a role in accelerating transmetalation. In addition, we show that sulfinate homocoupling is responsible for converting Pd(OAc)2 to a catalytically active Pd(0) complex. Together, these studies shed light on the challenges that must be overcome to deliver improved, lower temperature versions of these synthetically important processes.
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.
Scope and limitation of propylene carbonate as a sustainable solvent in the Suzuki-Miyaura reaction
Czompa, Andrea,Pásztor, Balázs László,Sahar, Jennifer Alizadeh,Mucsi, Zoltán,Bogdán, Dóra,Ludányi, Krisztina,Varga, Zoltán,Mándity, István M.
, p. 37818 - 37824 (2019/12/03)
The Suzuki-Miyaura reaction is one of the most used transformations in drug research. Thus making this reaction more sustainable is of considerable current interest. Here we show that propylene carbonate (PC) can be used as a solvent for the Suzuki-Miyaura reaction. PC is one of the greenest solvents since it is synthesized under green conditions by the use of carbon dioxide in the air. All reactions proceeded well and good or excellent yields were observed for the biaryl products. Nonetheless in the case of pyridazinones, 2-hydroxypropyl- chain containing side-products were observed. Importantly, this fact allowed the isolation of several novel compounds which were generated under prominently green conditions.
Ultralong room-temperature phosphorescence of a solid-state supramolecule between phenylmethylpyridinium and cucurbit[6]uril
Zhang, Zhi-Yuan,Liu, Yu
, p. 7773 - 7778 (2019/08/30)
Long-lived organic room-temperature phosphorescence (RTP) has received great attention because of its various potential applications. Herein, we report a persistent RTP of a solid-state supramolecule between a cucurbit[6]uril (CB[6]) host and a heavy-atom
Monoamine Oxidase (MAO-N) Whole Cell Biocatalyzed Aromatization of 1,2,5,6-Tetrahydropyridines into Pyridines
Toscani, Anita,Risi, Caterina,Black, Gary W.,Brown, Nicola L.,Shaaban, Ali,Turner, Nicholas J.,Castagnolo, Daniele
, p. 8781 - 8787 (2018/09/06)
A sustainable MAO-N biocatalyzed process for the synthesis of pyridines from aliphatic tetrahydropyridines (THP) has been developed. Pyridine compounds were synthesized under mild reaction conditions and with high conversion, exploiting MAO-N whole cells as aromatizing biocatalysts. The kinetic profile of the whole cell biocatalytic transformation was finally investigated via in situ 19F NMR.
Synthesis of Bi(hetero)aryls via Sequential Oxidation and Decarboxylation of Benzylamines in a Batch/Fully Automated Continuous Flow Process
Mahajan, Bhushan,Aand, Dnyaneshwar,Singh, Ajay K.
supporting information, p. 2831 - 2835 (2018/06/21)
Catalytic dehydrogenative cross-coupling of two C–H bonds represents a green strategy in view of the atom- and step-economy. However, the challenge is to discover a new innovative bond strategy, especially for the direct coupling between Csp2–H
ONE STEP DIRECT ARYLATION OF COMMODITY CHEMICALS TO SPECIALTY CHEMICALS BY TANDEM CATALYTIC PLATFORM
-
Paragraph 0044-0048; 0106, (2018/02/28)
The present invention relates to a continuous direct arylation process based on a tandem catalyst for synthesizing specialty chemicals. A method for synthesizing an aryl-aryl structure from a substrate selected from the group consisting of benzyl alcohol, benzyl amine and toluene which are low value added compounds is developed using a silver ion-containing tandem catalyst. The method is applied for synthesizing hexaphenyl arylene and can be applied for synthesizing high value added compounds (not only natural substances and chemical compounds but pharmaceutical and agricultural pesticide relative fields) directly from primary raw materials through the reaction.COPYRIGHT KIPO 2017
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.
