5963-51-9Relevant articles and documents
A concise palladium-catalyzed carboamination route to (±)- tylophorine
Rossiter, Lana M.,Slater, Meagan L.,Giessert, Rachel E.,Sakwa, Samuel A.,Herr, R. Jason
, p. 9554 - 9557 (2009)
(Chemical Equation Presented) Atotal synthesis of the racemic natural product tylophorine [(±)-1] has been demonstrated using the palladium-catalyzed carboamination method developed byWolfe and co-workers. In this case, an electron-rich aryl bromide 18 wa
Molybdenum-Catalyzed Deoxygenation Coupling of Lignin-Derived Alcohols for Functionalized Bibenzyl Chemicals
Jiang, Huifang,Lu, Rui,Luo, Xiaolin,Si, Xiaoqin,Xu, Jie,Lu, Fang
supporting information, p. 1292 - 1296 (2020/12/09)
With the growing demand for sustainability and reducing CO2 footprint, lignocellulosic biomass has attracted much attention as a renewable, carbon-neutral and low-cost feedstock for the production of chemicals and fuels. To realize efficient utilization of biomass resource, it is essential to selectively alter the high degree of oxygen functionality of biomass-derivates. Herein, we introduced a novel procedure to transform renewable lignin-derived alcohols to various functionalized bibenzyl chemicals. This strategy relied on a short deoxygenation coupling pathway with economical molybdenum catalyst. A well-designed H-donor experiment was performed to investigate the mechanism of this Mo-catalyzed process. It was proven that benzyl carbon-radical was the most possible intermediate to form the bibenzyl products. It was also discovered that the para methoxy and phenolic hydroxyl groups could stabilize the corresponding radical intermediates and then facilitate to selectively obtain bibenzyl products. Our research provides a promising application to produce functionalized aromatics from biomass-derived materials.
Luminescent tungsten(vi) complexes as photocatalysts for light-driven C-C and C-B bond formation reactions
Chan, Kaai-Tung,Che, Chi-Ming,Du, Lili,Liu, Yungen,Phillips, David Lee,To, Wai-Pong,Tong, Glenna So Ming,Wu, Liang-Liang,Yu, Daohong
, p. 6370 - 6382 (2020/07/15)
The realization of photocatalysis for practical synthetic application hinges on the development of inexpensive photocatalysts which can be prepared on a large scale. Herein an air-stable, visible-light-absorbing photoluminescent tungsten(vi) complex which can be conveniently prepared at the gram-scale is described. This complex could catalyse photochemical organic transformation reactions including borylation of aryl halides, such as aryl chloride, reductive coupling of benzyl bromides for C-C bond formation, reductive coupling of phenacyl bromides, and decarboxylative coupling of redox-active esters of alkyl carboxylic acid with high product yields and broad functional group tolerance.
Photo-catalytic preparation method of bibenzyl compounds
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Paragraph 0058-0061; 0064, (2020/02/27)
The invention relates to a preparation method of bibenzyl compounds. A compound represented by a formula (A) and a compound represented by a formula (C) carry out reactions under the action of an organic tungsten catalyst and an alkali in the presence of light to generate bibenzyl compounds represented by the formula (B). The method is simple and is easy to operate. The yield is high, and the application range is wide. Moreover, the invention also provides an application of a tungsten complex in organic chemical reactions as a photocatalyst.
Dihedral-Angle-Controlled Crossover from Static Hole Delocalization to Dynamic Hopping in Biaryl Cation Radicals
Talipov, Marat R.,Navale, Tushar S.,Hossain, Mohammad M.,Shukla, Ruchi,Ivanov, Maxim V.,Rathore, Rajendra
supporting information, p. 266 - 269 (2016/12/30)
In cases of coherent charge-transfer mechanism in biaryl compounds the rates follow a squared cosine trend with varying dihedral angle. Herein we demonstrate using a series of biaryl cation radicals with varying dihedral angles that the hole stabilization
Aerobic Oxidative Intramolecular Aromatic Coupling via Heterogeneous Metal Catalysts
Fujimoto, Shigenobu,Matsumoto, Kenji,Shindo, Mitsuru
supporting information, p. 3057 - 3061 (2016/10/09)
An aerobic, heterogeneously catalyzed oxidative intramolecular coupling reaction of aromatic compounds is reported here. Using commercially available, recyclable heterogeneous metal catalysts, the coupling reactions of o-terphenyls and 1,ω-biarylalkanes proceeded quickly under mild conditions, i.e., at room temperature under oxygen as a co-oxidant almost all within 1 h, to provide the corresponding coupled products like triphenylenes and phenanthrenes in good to excellent yields. This reaction is an easily handled, practical, and atom-economical coupling method, which is of great importance in modern organic syntheses. (Figure presented.).
Total synthesis of the marine metabolite (±)-Polysiphenol via highly regioselective intramolecular oxidative coupling
Barrett, Tim N.,Braddock, D. Christopher,Monta, Anna,Webb, Michael R.,White, Andrew J.P.
supporting information; experimental part, p. 1980 - 1984 (2011/11/11)
(±)-Polysiphenol (1), an atropisomerically stable 4,5-dibrominated 9,10-dihydrophenanthrene from Polysiphonia ferulacea, was prepared by a biomimetically inspired highly regioselective intramolecular oxidative coupling of a dibrominated dihydrostilbene. T
Total synthesis of (S)-(+)-tylophorine via enantioselective intramolecular alkene carboamination
Zeng, Wei,Chemler, Sherry R.
, p. 6045 - 6047 (2008/12/21)
(Chemical Equation Presented) The enantioselective synthesis of (S)-(+)-tylophorine, a potent cancer cell growth inhibitor, has been accomplished in eight steps from commercially available 3,4-dimethoxybenzyl alcohol. A copper (II)-catalyzed enantioselective intramolecular alkene carboanimation was employed as the key step to construct the chiral indolizidine ring.
Couplings of benzylic halides mediated by titanocene chloride: Synthesis of bibenzyl derivatives
Barrero, Alejandro F.,Herrador, M. Mar,Del Moral, Jose F. Quilez,Arteaga, Pilar,Akssira, Mohammed,El Hanbali, Fadwa,Arteaga, Jesus F.,Dieguez, Horacio R.,Sanchez, Elena M.
, p. 2251 - 2254 (2007/10/03)
Titanocene monochloride catalyzes the homocoupling of benzylic halides and benzylic gem-dibromides to give the corresponding bibenzyl and stilbenyl systems. Exposure of benzylic bromides to Ti(III) in the presence of aldehydes gave rise to the Barbier-type products. Examples of the utility of the herein described processes are included.
A simple route to new phenanthro- and phenanthroid-fused thiazoles by a PIFA-mediated (hetero)biaryl coupling reaction
Moreno, Isabel,Tellitu, Imanol,Dominguez, Esther,SanMartin, Raul
, p. 2126 - 2135 (2007/10/03)
An application of the PIFA-mediated [PIFA: phenyliodine(III) bis(trifluoroacetate) biaryl coupling reaction is presented and extended to the formation of heterobiaryl connections. A preliminary study of the scope and limitations of this procedure was carried out in the synthesis of phenanthroids 11 from a series of phenethyl-substituted heterocycles 10, It was observed that in some cases a competitive dimerization process took place. It was also found that the coupling step could be efficiently extended to a larger number of examples if an aromatic ring were situated fused to the 1,2-diarylethane skeleton, as in 23 and 30. The synthesis of a series of 4,5-diarylthiazoles 23a-g was therefore carried out to explore the electronic requirements and the regioselectivity of the PIFA-mediated non-phenolic coupling reaction. When the same procedure was applied to aryl-heteroarylthiazoles 30, a series of phenanthroid-fused thiazoles 31 was obtained in good overall yields. To the best of our knowledge, no oxidative aryl-heteroaryl coupling reaction of this type had previously been reported. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
