16611-67-9Relevant academic research and scientific papers
Asymmetric Transfer Hydrogenation of Diaryl Ketones with Ethanol Catalyzed by Chiral NCP Pincer Iridium Complexes
Huang, Zheng,Liu, Guixia,Qian, Lu,Tang, Xixia,Wang, Yulei
supporting information, (2022/02/23)
The use of a chiral (NCP)Ir complex as the precatalyst allowed for the discovery of asymmetric transfer hydrogenation of diaryl ketones with ethanol as the hydrogen source and solvent. This reaction was applicable to various ortho-substituted diaryl keontes, affording benzhydrols in good yields and enantioselectivities. This protocol could be carried out in a gram scale under mild reaction conditions. The utility of the catalytic system was highlighted by the synthesis of the key precursor of (S)-neobenodine.
Highly Enantioselective Cobalt-Catalyzed Hydroboration of Diaryl Ketones
Liu, Wenbo,Guo, Jun,Xing, Shipei,Lu, Zhan
supporting information, p. 2532 - 2536 (2020/04/02)
A highly enantioselective cobalt-catalyzed hydroboration of diaryl ketones with pinacolborane was developed using chiral imidazole iminopyridine as a ligand to access chiral benzhydrols in good to excellent yields and ee. This protocol could be carried out in a gram scale under mild reaction conditions with good functional group tolerance. Chiral biologically active 3-substituted phthalide and (S)-neobenodine could be easily constructed through asymmetric hydroboration as a key step.
Cobalt-Catalyzed Asymmetric Hydrogenation of 1,1-Diarylethenes
Chen, Jianhui,Chen, Chenhui,Ji, Chonglei,Lu, Zhan
supporting information, p. 1594 - 1597 (2016/05/02)
Highly enantioselective cobalt-catalyzed hydrogenation of 1,1-diarylethenes was developed by using bench-stable chiral oxazoline iminopyridine-cobalt complexes as precatalysts. A unique o-chloride effect was observed to achieve high enantioselectivity. Easy removal as well as further transformations of the chloro group make this protocol a potentially useful alternative to synthesize various chiral 1,1-diarylethanes. This process can be successfully performed under 1 atm of hydrogen at room temperature on gram scale.
Directed magnesiation of polyhaloaromatics using the tetramethylpiperidylmagnesium reagents TMP2Mg×2 LiCl and TMPMgCl×LiCl
Unsinn, Andreas,Rohbogner, Christoph J.,Knochel, Paul
supporting information, p. 1553 - 1560 (2013/06/27)
A convenient and efficient functionalization of polyhaloaromatics via regioselective magnesiation has been developed. Starting from simple, inexpensive but structurally challenging arenes, metallation by magnesium amide bases was achieved under mild conditions. The desired Grignard reagents were stable towards aryne formation, were obtained in good yields within short reaction times and could be reacted with a variety of typical electrophiles, providing attractive, functionalized building blocks in good to excellent yields. As an application we have prepared the antimicrobial natural product 2,6-dichloro-3-phenethylphenol isolated from the New Zealand liverwort Riccardia marginata. This synthesis involves a mixed bimetallic compound prepared via metallation of a phenylboronic acid pinacol ester derivative and subsequent selective cross-coupling. Copyright
Synthesis of (2-chlorophenyl)(phenyl)methanones and 2-(2-chlorophenyl)-1- phenylethanones by Friedel-Crafts acylation of 2-chlorobenzoic acids and 2-(2-chlorophenyl)acetic acids using microwave heating
Mahdi, Jasia,Ankati, Haribabu,Gregory, Jill,Tenner, Brian,Biehl, Edward R.
, p. 2594 - 2596 (2011/06/21)
Several 2-(2-chlorophenyl)-1-phenylethanones and (2-chlorophenyl)(phenyl) methanones were prepared by the Friedel-Crafts acylation reaction of 2-(2-chlorophenyl) acetic acids and 2-chlorocarboxylic acids, respectively, in the presence of cyanuric chloride, pyridine, and AlCl3 or FeCl 3 using microwave heating. The yields of the ketones were significantly higher than those obtained using conventional heating. In addition, similar reactions carried out with the less inexpensive and less toxic FeCl3 gave titled ketones in comparable yields. Interestingly, the FeCl3 catalyzed reactions gave pure ketones (no chromatographic purification required), whereas the AlCl3 catalyzed reaction gave impure product that required chromatographic purification.
Crystal structures of 2-chloro- and 2,5-dichloro-benzophenones
Pinkus,Klausmeyer,Feazell,Meng,Chang
, p. 637 - 640 (2007/10/03)
The crystal structures of 2-chlorobenzophenone (1) and 2,5- dichlorobenzophenone (2) were obtained by single-crystal X-ray diffraction. Crystallization of 1 occurs in the centrosymmetric monoclinic space group P21/c (No. 14) with a = 8.2812(8), b = 16.5933(1), c = 7.7599(7); β = 98.488(5)°and Z = 4. Crystallization of 2 occurs in the centrosymmetric orthorhombic space group Pbca (No. 61) with a = 16.414(3), b = 7.7896(1), and c = 17.754(4); and Z = 8. Details of the structures and spectroscopic results are presented and discussed. Torsion angles about the carbonyl functionality were found to be outside the previously observed values for unsubstituted benzophenones by greater than 20°.
Advances in Ni(0)-catalyzed coupling for the synthesis of polythiophenes and polyphenylenes
Hagberg, Erik C.,Olson, David A.,Sheares, Valerie V.
, p. 4748 - 4754 (2007/10/03)
The effects of solvent and monomer structure on the Ni(0)-catalyzed polymerization of 2,5-dichloro-3-(2′-thiophenecarbonyl)thiophene, 3-benzenesulfonyl-2,5-dichlorothiophene, 2,5-dichlorobenzophenone, and 2-benzenesulfonyl-1,4-dichlorobenzene were explored. Poly[3-(2′- thiophenecarbonyl)-2,5-thiophene] with an intrinsic viscosity of 0.38 dL/g and a 10% weight loss temperature in nitrogen of 480 °C (Tg = 149 °C) was synthesized. Oligomeric material was prepared from 3-benzenesulfonyl-2,5-dichlorothiophene. Poly(2,5-benzophenone) of 58 × 103 g/mol ([η] = 1.15 dL/g) with a Tg of 180 °C and a 10% weight loss temperature in nitrogen of 576 °C was synthesized. Oligomeric materials were also obtained from the polymerization of 2-benzenesulfonyl-1,4-dichlorobenzene. It was shown that the solvent choice has drastic effects upon the catalyst system and the final polymer. The differences in the catalyst resulting from solvent choice were explored by nuclear magnetic resonance. Effects arising from the structure of the monomer are discussed in relationship to the results obtained and the proposed mechanism.
Preparation of 2,5-dichlorobenzophenones
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, (2008/06/13)
A method for preparing isomerically pure 2,5-dichlorobenzophenones in good to high yields is provided. The invention comprises Friedel-Crafts aroylation of 1,4-dichlorobenzene using an aroyl halide or aromatic anhydride and at least one Lewis acid, the latter being present in an amount of at least about 1.1 mole per mole of aroyl halide or aromatic anhydride, preferably about 1.5 moles per mole of aroyl halide or aromatic anhydride and, more preferably, from about 2 to about 2.5 moles of Lewis acid per mole of aroyl halide or aromatic anhydride. Preferably, the molar ratio of 1,4-dichlorobenzene to aroyl halide ranges from about 1.2:1 to about 8:1.
