4423-10-3Relevant academic research and scientific papers
Oxidative reactions of azines. 11. The influence of manganese dioxide on the reaction of tetrahydropyridines with formaldehyde: Synthesis and molecular structures of 3-oxa-7-azabicyclo[3.3.1]- and 6-oxa-2-azabicyclo[3.2.1]octanes
Soldatenkov,Polyanskii,Temesgen,Sergeeva,Vysotskaya,Averkiev,Antipin,Lobanov
, p. 641 - 649 (2004)
New derivatives of piperidino[4,5-d]dioxane and 3-oxa-7-bicyclo[3.3.1] nonane were obtained by the oxidatively catalysed condensation of 4-aryl-1,2,3,6-tetrahydropyridines with formaldehyde. The direction of this reaction is sharply altered in the presence of manganese dioxide to give 6-oxa-2-azabicylo[3.2.1]octan-4-one - the product of the oxidative condensation of a new type.
Prins reaction under manganese dioxide control: The synthesis of 6-oxa-2-azabicyclo[3.2.1]octan-4-ones from tetrahydropyridines and formaldehyde
Soldatenkov,Polyanskii,Temesgen,Soldatova,Sergeeva,Kolyadina,Lobanov
, p. 27 - 28 (2001)
The course of the acid-catalysed Prins reaction of tetrahydropyridines 1 with formaldehyde, leading to derivatives of piperidino-dioxane 4 and 3-oxa-7-azabicyclononanes 5 and 6, is dramatically changed in the presence of manganese dioxide to give new products, 6-oxa-2-azabicyclo[3.2.1]octan-4-ones 7 and 8.
One-pot condensation of 2-arylpropenes with formaldehyde and ammonium chloride: The synthesis of aryl substituted pyridines and 5,7,11-trioxa-1-azatricyclo[7.3.1.03,8]tridecanes
Soldatenkov,Polyanskii,Temesgen,Soldatova,Sergeeva,Kolyadina,Lobanov
, p. 154 - 155 (2001)
A mixture consisting of 2-arylpropene 1 or 2, formaldehyde and ammonium chloride condenses in a one-pot manner to yield 5,7,11-trioxa-1-azatricyclo [7.3.1.03,8]tridecanes 3 or 4. In the presence of manganese dioxide the reaction leads to 4-arylpyridines 5 or 6.
A novel ring transformation of pyridinium salts as a route to 4-arylpyridines
Gromov, Sergey P.,Kurchavov, Nikolai A.
, p. 4123 - 4126 (2002)
Regiospecific phenylation of pyridine derivatives at the 4-position takes place in the reaction of 4-methylpyridinium salts 1 with other pyridinium salts 2 by intermolecular transformation of the pyridine ring in 1 and participation of the methyl group of 2. The method developed makes it possible to carry out ring transformation not only for pyridinium salts 1 but even for pyridine itself. 4-Phenylpyridine (3) was produced in 29-57% yields. The new reaction proceeds in an aqueous medium on heating and on treatment with methylammonium sulfite. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2002.
Tunable Second-Level Room-Temperature Phosphorescence of Solid Supramolecules between Acrylamide–Phenylpyridium Copolymers and Cucurbit[7]uril
Xu, Wen-Wen,Chen, Yong,Lu, Yi-Lin,Qin, Yue-Xiu,Zhang, Hui,Xu, Xiufang,Liu, Yu
supporting information, (2021/12/24)
A series of solid supramolecules based on acrylamide–phenylpyridium copolymers with various substituent groups (P?R: R=?CN, ?CO2Et, ?Me, ?CF3) and cucurbit[7]uril (CB[7]) are constructed to exhibit tunable second-level (from 0.9 s to
Cobalt-catalyzed cross-coupling of nitrogen-containing heterocyclic phosphonium salts with arylmagnesium reagents
Cui, Yan-Ying,Na, Jin-He,Guo, Meng-Meng,Huang, Jie-Ying,Chu, Xue-Qiang,Rao, Weidong,Shen, Zhi-Liang
supporting information, (2022/02/16)
Cobalt-catalyzed cross-couplings of nitrogen-containing heterocyclic phosphonium salts with arylmagnesium halides proceeded efficiently with the aid of cobalt(II) catalyst and copper(I) salt in tetrahydrofuran at ambient temperature, producing the desired
Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
, p. 208 - 218 (2021/12/29)
A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
New Nickel-Based Catalytic System with Pincer Pyrrole-Functionalized N-Heterocyclic Carbene as Ligand for Suzuki-Miyaura Cross-Coupling Reactions
Guo, Zhifo,Lei, Xiangyang
supporting information, (2021/09/11)
A new catalytic system with Ni(NO3)2·6H2O as the catalyst and a pincer pyrrole-functionalized N-heterocyclic carbene as the ligand was employed in the Suzuki-Miyaura cross-coupling reactions of aryl iodides with arylboronic acids. With 5 mol% catalyst, the catalytic reactions proceeded at 160 °C, giving coupling products in isolated yields of up to 94% in short reaction times (1-4 h). The system worked efficiently with aryl iodides bearing electron-donating or electron-withdrawing groups and arylboronic acids with electron-donating groups. Steric effects were observed for both aryl iodides and arylboronic acids. It is proposed that the reactions underwent a Ni(I)/Ni(III) catalytic cycle.
Practical and Regioselective Synthesis of C-4-Alkylated Pyridines
Baran, Phil S.,Choi, Jin,Godineau, Edouard,Laudadio, Gabriele
, p. 11927 - 11933 (2021/08/20)
The direct position-selective C-4 alkylation of pyridines has been a long-standing challenge in heterocyclic chemistry, particularly from pyridine itself. Historically this has been addressed using prefunctionalized materials to avoid overalkylation and mixtures of regioisomers. This study reports the invention of a simple maleate-derived blocking group for pyridines that enables exquisite control for Minisci-type decarboxylative alkylation at C-4 that allows for inexpensive access to these valuable building blocks. The method is employed on a variety of different pyridines and carboxylic acid alkyl donors, is operationally simple and scalable, and is applied to access known structures in a rapid and inexpensive fashion. Finally, this work points to an interesting strategic departure for the use of Minisci chemistry at the earliest possible stage (native pyridine) rather than current dogma that almost exclusively employs Minisci chemistry as a late-stage functionalization technique.
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.
