- A practical synthesis of highly hindered biphenyl-2-carboxylates via nucleophilic aromatic substitution of tert-butyl 2-methoxybenzoates with aryl grignard reagent
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The fluorenone derivative (OPC-34165) has potent repairing and protecting activities for peripheral and central nervous system degeneration. A synthesis of the biphenyl-2-carboxylic acid derivative, which is the key intermediate of OPC-34165, is described employing the SNAr reaction of tert-butyl 2-methoxybenzoate with aryl Grignard reagent in refluxing THF-toluene.
- Aki, Shinji,Haraguchi, Yoshikazu,Sakikawa, Hiroshi,Ishigami, Masashi,Fujioka, Takafumi,Furuta, Takuya,Minamikawa, Jun-Ichi
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- Tri-Manganese(III) Salen-Based Cryptands: A Metal Cooperative Antioxidant Strategy that Overcomes Ischemic Stroke Damage in Vivo
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Oxidative stress is one of the hallmarks of ischemic stroke. Catalase-based (CAT) biomimetic complexes are emerging as promising therapeutic candidates that are expected to act as neuroprotectants for ischemic stroke by decreasing the damaging effects fro
- Du, Yujing,Gao, Song,Huo, Yan,Jiang, Shang-Da,Kang, Lei,Li, Cuicui,Lin, Hengyu,Ning, Yingying,Sedgwick, Adam C.,Sessler, Jonathan L.,Wang, Bing-Wu,Xue, Haozong,Yao, Yuhang,Zhang, Jun-Long
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supporting information
p. 10219 - 10227
(2020/06/27)
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- Cage-shaped borate esters with tris(2-oxyphenyl)methane or -silane System frameworks bearing multiple tuning factors: Geometric and substituent effects on their lewis acid properties
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Boron complexes that contain new tridentate ligands, tris(o-oxyaryl) methanes and -silanes, were prepared. These complexes had a cage-shaped structure around a boron center and showed higher Lewis acidity and catalytic activity than open-shaped boron compounds. The cage-shaped ligands determined the properties of the borates by altering the geometry and were consistently bound to the metal center by chelation. The synthesized compounds were L·B(OC6H4)3CH, L·B(OC 6H4)3SiMe, and its derivatives (L=THF or pyridine as an external ligand). Theoretical calculations suggested that the cage-shaped borates had a large dihedral angle (Cipso-O-B-O) compared with open-shaped borates. The geometric effect due to the dihedral angle means that compared with open-shaped, the cage-shaped borates have a greater Lewis acidity. The introduction of electron-withdrawing groups on the aryl moieties in the cage-shaped framework increased the Lewis acidity. Substitution of a bridgehead Si for a bridgehead C decreased the Lewis acidity of the boron complexes because the large silicon atom reduces the dihedral angle of C ipso-O-B-O. The ligand-exchange rates of the para-fluoro-substituted compound B(OC6H3F)3CH and the ortho-phenyl-substituted compound B(OC6H3Ph)3CH were less than that of the unsubstituted borate B(OC6H 4)3CH. The ligand-exchange rate of B(OC6H 4)3SiMe was much faster than that of B(OC 6H4)3CH. A hetero Diels-Alder reaction and Mukaiyama-type aldol reactions were more effectively catalyzed by cage-shaped borates than by the open-shaped borate B(OPh)3 or by the strong Lewis acid BF3·OEt2. The cage-shaped borates with the bulky substituents at the ortho-positions selectively catalyzed the reaction with less sterically hindered substrates, while the unsubstituted borate showed no selectivity.
- Yasuda, Makoto,Nakajima, Hideto,Takeda, Ryosuke,Yoshioka, Sachiko,Yamasaki, Satoshi,Chiba, Kouji,Baba, Akio
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scheme or table
p. 3856 - 3867
(2011/05/16)
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- Diaroyl tellurides: Synthesis, structure and NBO analysis of (2-MeOC 6H4CO)2Te - comparison with its sulfur and selenium isologues. The first observation of [MgBr][R(C=Te)O] salts
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A series of aromatic diacyl tellurides were prepared in moderate to good yields by the reactions of sodium or potassium arenecarbotelluroates with acyl chlorides in acetonitrile. X-ray structure analyses and theoretical calculations of 2-methoxybenzoic an
- Niyomura, Osamu,Nakaiida, Shoho,Yamada, Ryo,Kato, Shinzi,Ishida, Masaru,Ebihara, Masahiro,Ando, Fumio,Koketsu, Jugo
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experimental part
p. 2555 - 2572
(2009/12/03)
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- Cage-shaped borate esters with enhanced Lewis acidity and catalytic activity
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A cage shape causes high Lewis acidity and catalytic activity on boron. Borate esters that have cage-shaped ligands have accessible LUMO with lower eigenvalues than normal open-shaped borate esters. A large dihedral angle at C-O-B-O in cage-shaped borate
- Yasuda, Makoto,Yoshioka, Sachiko,Yamasaki, Satoshi,Somyo, Toshio,Chiba, Kouji,Baba, Akio
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p. 761 - 764
(2007/10/03)
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- A new heptacoordinated organogermanium compound; trichlorogermyl[tris(2-methoxyphenyl)]methane
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A new hypercoordinated organogermanium compound, trichlorogermyl[tris(2-methoxyphenyl)]methane (4) was prepared, and its tricapped tetrahedral structure was confirmed by X-ray crystallographic analysis. All interatomic oxygen...germanium distances are sho
- Takeuchi, Yoshito,Takase, Yutaka
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p. 3275 - 3277
(2007/10/03)
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- (4-Methoxyphenyl)diphenylmethanol, an unusual tetramer containing a D[R] pattern of hydrogen bonds, and tris(2-methoxyphenyl)methanol
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(4-Methoxyphenyl)diphenylmethanol (C20H18O2) crystallizes with two independent molecules; the molecules are linked by O-H...O hydrogen bonds into centrosymmetric tetramers in which two molecules form a cyclic R22(16) motif from which the other two are pendant, giving a D33(11)[R22(16)] pattern. In tris(2-methoxyphenyl)methanol (C22H22O4) the hydroxy H atoms are disordered over two sites; whichever site is occupied, an intramolecular O-H...O hydrogen bond is formed with a methoxy O atom.
- Patterson, Iain L. J.,Glidewell, Christopher,Ferguson, George
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p. 1970 - 1974
(2007/10/03)
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- Synthesis of highly crowded cyclopentadienes via reactions of Cp2Ni and CpSn(CH3)3 with triarylmethylhalogenides. Molecular structure of 1-(CH3)3Si-(3-Ph3C)-C5H4
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Triphenylmethylcyclopentadiene Ph3CC5H5 (1) and 2-cyclopentadiene 2-((2'-CH3OC6H4)3C)C5H5 (2) have been prepared in high yields via reactions of the corresponding triarylmethyl-halogenides with Cp2Ni (and CpSn(CH3)3 in the c
- Rufanov, Konstantin A.,Kazennova, Nadezhda B.,Churakov, Andrew V.,Lemenovskii, Dmitry A.,Kuz'mina, Ludmila G.
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p. 173 - 178
(2007/10/02)
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- The Dehydrogenation of Alcohols with Tris-(o-methoxyphenyl)carbenium Chloride.
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Heptan-1-ol, benzyl alcohol, and cyclohexanol are dehydrogenated by tris-(o-methoxyphenyl)carbenium chloride (2) in dichloromethane solution under mild conditions without concomitant formation of quinonoid adducts (6) (through the intermediacy of which part of the alcohols would be trapped and escape oxidation).The yields of the resulting benzaldehyde and cyclohexanone are good to excellent; but the yield of the saturated aldehyde heptanal is at best moderate.In contrast to benzaldehyde and cyclohexanone, heptanal is sensitive to the reagent (2) under the prevailing conditions, and is further transformed into mixtures of heptanoic acid, heptyl heptanoate and 2-pentylnon-2-enal.
- Huszthy, Peter,Lempert, Karoly,Simig, Gyula,Tamas, Jozsef,Hegedus-Vajda, Judit,Almasy, Attila
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p. 2524 - 2540
(2007/10/02)
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