6153-92-0Relevant articles and documents
Dehydrogenative Synthesis of 2,2′-Bipyridyls through Regioselective Pyridine Dimerization
Yamada, Shuya,Kaneda, Takeshi,Steib, Philip,Murakami, Kei,Itami, Kenichiro
supporting information, p. 8341 - 8345 (2019/04/30)
2,2′-Bipyridyls have been utilized as indispensable ligands in metal-catalyzed reactions. The most streamlined approach for the synthesis of 2,2′-bipyridyls is the dehydrogenative dimerization of unfunctionalized pyridine. Herein, we report on the palladium-catalyzed dehydrogenative synthesis of 2,2′-bipyridyl derivatives. The Pd catalysis effectively works with an AgI salt as the oxidant in the presence of pivalic acid. A variety of pyridines regioselectively react at the C2-positions. This dimerization method is applicable for challenging substrates such as sterically hindered 3-substituted pyridines, where the pyridines regioselectively react at the C2-position. This reaction enables the concise synthesis of twisted 3,3′-disubstituted-2,2′-bipyridyls as an underdeveloped class of ligands.
Structural and Synthetic Insights into Pyridine Homocouplings Mediated by a β-Diketiminato Magnesium Amide Complex
Davin, Laia,Clegg, William,Kennedy, Alan R.,Probert, Michael R.,McLellan, Ross,Hevia, Eva
supporting information, p. 14830 - 14835 (2018/09/25)
The reaction of [(DippNacnac)Mg(TMP)] (1) with 4-subtituted pyridines proceeds via sequential regioselective metallation and 1,2-addition to furnish a range of symmetric 4,4′-R2-2,2′-bipyridines in good yield, representing a new entry into bipyridine synthesis. Interestingly, the reaction of 1 with 2-OMe-pyridine led to formation of asymmetric bipyridine 6, resulting from the C6-magnesiation of the heterocycle followed by a C?C coupling step by addition to the C2 position of a second, non-metallated molecule, and subsequent elimination of [DippNacnacMgOMe]2 (7). Synthesis combined with spectroscopic and structural analysis help rationalise the underlying processes resulting in the observed reactivity, and elucidate the key role that the sterically encumbered β-diketiminate ligand plays in determining regioselectivity.
MANUFACTURING METHOD OF BIPYRIDYL COMPOUND
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Paragraph 0083; 0090; 0091; 0100-0102, (2017/09/16)
PROBLEM TO BE SOLVED: To provide various bipyridyl compounds by a reaction less in process number with a relief condition and short time. SOLUTION: A compound represented by the general formula, where Y represents a hydrogen atom or a nitrogen atom, R1 represents a cyano group, a halogen atom, an alkyl group which may be substituted, an alkoxy group which may be substituted, an aryl group which may be substituted, a heteroaryl group which may be substituted or a silyl group which may be substituted, n represents an integer of 0 to 4 and 2 R1 binding same benzene ring may bind each other to form a ring when n is 2 or more. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
Mechanistic insights into the potassium: Tert -butoxide-mediated synthesis of N-heterobiaryls
Stephens, David E.,Lakey-Beitia, Johant,Burch, Jessica E.,Arman, Hadi D.,Larionov, Oleg V.
supporting information, p. 9945 - 9948 (2016/08/11)
We report herein that symmetrical and non-symmetrical N-heterobiaryls are produced by a potassium tert-butoxide-mediated dimerization of heterocyclic N-oxides. The reaction is scalable and transition metal-free, and can be carried out under thermal and microwave conditions. Preliminary mechanistic studies point to the involvement of radical anionic intermediates arising from the N-oxide substrates and potassium tert-butoxide.
Electronic optimization of heteroleptic Ru(II) bipyridine complexes by remote substituents: Synthesis, characterization, and application to dye-sensitized solar cells
Han, Won-Sik,Han, Jung-Kyu,Kim, Hyun-Young,Choi, Mi Jin,Kang, Yong-Soo,Pac, Chyongjin,Kang, Sang Ook
, p. 3271 - 3280 (2011/06/22)
We prepared a series of new heteroleptic ruthenium(II) complexes, Ru(NCS)2LL0 (3a-3e), where L is 4,40-di(hydroxycarbonyl)-2,20-bipyridine and L0 is 4,40-di(p-Xphenyl)- 2,20-pyridine (X = CN (a), F (b), H (c), OMe (d), and NMe2 (e)), in an attempt to explore the structure-activity relationships in their photophysical and electrochemical behavior and in their performance in dye-sensitized solar cells (DSSCs). When substituent X is changed from electron-donating NMe2 to electron-withdrawing CN, the absorption and emission maxima reveal systematic bathochromic shifts. The redox potentials of these dyes are also significantly influenced by X. The electronic properties of the dyes were theoretically analyzed using density functional theory calculations; the results show good correlations with the experimental results. The solar-cell performance of DSSCs based on dye-grafted nanocrystalline TiO2 using 3a-3e and standard N3 (bis[(4,40-carboxy-2,20-bipyridine)(thiocyanato)]ruthenium(II)) were compared, revealing substantial dependences on the dye structures, particularly on the remote substituent X. The 3d-based device showed the best performance: η = 8.30%, JSC = 16.0 mA 3 cm-2, VOC = 717 mV, and ff = 0.72. These values are better than N3-based device. 2011 American Chemical Society. 2011 American Chemical Society.
Photochemistry of hetero-tris-chelated ruthenium(II) polypyridine complexes in dichloromethane
Jones Jr., Wayne E.,Smith, Robert A.,Abramo, Marsha T.,Williams, Michael D.,Van Houten
, p. 2281 - 2285 (2008/10/08)
The results of an investigation of the photochemical and photophysical properties of a series of complexes of the type [RuL2L′]Cl2 are reported, where L and L′ are bipyridine, phenanthroline, and methyl and phenyl derivatives of those ligands. All measurements were conducted in CH2Cl2. Luminescence lifetime and quantum yield data indicate that the ligand which accepts the electron in the localized MLCT excited state plays a significant role in the excited-state decay. HPLC analysis of the organic photoproducts from mixed-ligand complexes shows that flexible bipyridyl ligands are preferentially photolabilized, consistent with a dissociative mechanism involving an open-ended bipyridine in the transition state.
