- Synthesis method of 4-(4'-alkylcyclohexyl)cyclohexanol
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The invention discloses a novel method for synthesizing cis-trans mixed 4-(4'-alkylcyclohexyl)cyclohexanol by taking biphenyl as a starting raw material through five steps of reactions including Friedel-Crafts acylation reaction, Friedel-Crafts alkylation reaction, reduction reaction, oxidation reaction and catalytic hydrogenation. The method is mild in reaction condition, good in selectivity, high in yield, convenient to operate, environmentally friendly and suitable for industrial production.
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Paragraph 0080-0081
(2021/02/13)
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- Light-DrivenN-Heterocyclic Carbene Catalysis Using Alkylborates
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Radical-radical coupling, the selective reaction between two different radical species, has contributed to the methodology for connecting bulky units. Light-drivenN-heterocyclic carbene (NHC) organocatalysis is recognized as a state-of-the-art methodology enabling radical-radical coupling. The catalytic process involves forming an acyl azolium intermediate from the NHC catalyst and an acyl donor, followed by single electron reduction of this key intermediate, which is largely dependent on the photoredox catalyst. We designed a radical NHC catalysis in which the direct photoexcitation of a borate to form a high reducing agent facilitated the single electron reduction event. The borate produces an alkyl radical for the single electron transfer process to accomplish the radical-radical coupling. This protocol enables cross-coupling between alkylborates and acyl imidazoles in addition to radical relay-type alkylacylations of alkenes with alkylborates and acyl imidazoles, affording ketones with a broad scope.
- Sato, Yukiya,Goto, Yamato,Nakamura, Kei,Miyamoto, Yusuke,Sumida, Yuto,Ohmiya, Hirohisa
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p. 12886 - 12892
(2021/10/29)
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- Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
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The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes via boron enolate intermediates, and the subsequent Rh-catalyzed dehydrogenative borylation of alkenes leads to the formation of vinylboronates and diboration products, which is also supported by density functional theory calculations.
- Tao, Lei,Guo, Xueying,Li, Jie,Li, Ruoling,Lin, Zhenyang,Zhao, Wanxiang
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p. 18118 - 18127
(2020/11/26)
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- Scalable Aerobic Oxidation of Alcohols Using Catalytic DDQ/HNO3
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A selective, practical, and scalable aerobic oxidation of alcohols is described that uses catalytic amounts of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HNO3, with molecular oxygen serving as the terminal oxidant. The method was successfully applied to the oxidation of a wide range of benzylic, propargylic, and allylic alcohols, including two natural products, namely, carveol and podophyllotoxin. The conditions are also applicable to the selective oxidative deprotection of p-methoxybenzyl ethers.
- Arseniyadis, Stellios,Clavier, Louis,Copin, Chloé,Fournier, Jean,Giffard, Jean-Fran?ois,Jean, Alexandre,Katsina, Tania,Macedo Portela Da Silva, Nayane,Tamion, Rodolphe
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supporting information
p. 856 - 860
(2020/07/14)
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- Suzuki-Miyaura coupling of simple ketones via activation of unstrained carbon-carbon bonds
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Here, we describe that simple ketones can be efficiently employed as electrophiles in Suzuki-Miyaura coupling reactions via catalytic activation of unstrained C-C bonds. A range of common ketones, such as cyclopentanones, acetophenones, acetone and 1-indanones, could be directly coupled with various arylboronates in high site-selectivity, which offers a distinct entry to more functionalized aromatic ketones. Preliminary mechanistic study suggests that the ketone α-C-C bond was cleaved via oxidative addition.
- Xia, Ying,Wang, Jianchun,Dong, Guangbin
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supporting information
p. 5347 - 5351
(2018/05/03)
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- One-pot sequential 1,2-addition, Pd-catalysed cross-coupling of organolithium reagents with Weinreb amides
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An efficient sequential 1,2-addition/cross-coupling of Weinreb amides with two organolithium reagents is reported. This synthetic approach allows access to a wide variety of functionalized ketones in a modular way. The one-pot procedure presented here takes advantage of a kinetically stable tetrahedral Weinreb intermediate during subsequent Pd-catalyzed cross-coupling with the second organolithium reagent leading, within short reaction times and under mild conditions, to the formation of ketones in excellent overall yields.
- Giannerini,Vila,Hornillos,Feringa
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supporting information
p. 1206 - 1209
(2016/01/15)
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- Nanocrystalline titania-supported palladium(0) nanoparticles for Suzuki-Miyaura cross-coupling of aryl and heteroaryl halides
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The Suzuki cross-coupling reaction of various aryl and heteroaryl halides with arylboronic and heteroarylboronic acids was studied using a titania-supported palladium(0) catalyst at room temperature under air. The conversion and selectivity results obtained for many substrates were excellent and similar to those provided by more active or even homogeneous catalysts. The methodology is similarly effective using 2-bromo-3,4,5-trimethoxybenzaldehyde as the coupling partner and gave products in good yield. Furthermore, it has been shown that it is useful for the synthesis of terphenyl and tetraphenyls. The catalyst is quantitatively recovered from the reaction by simple filtration and reused for a number of cycles without significant loss of activity. Inductively coupled plasma (ICP) mass-spectrometric analysis of the filtrate from the reaction mixture demonstrated that the palladium metal hardly leached into the solution within the limits of the detector (1 ppm), thus suggesting that the present Suzuki-Miyaura reaction proceeded by heterogeneous catalysis. Copyright
- Sreedhar,Yada, Divya,Reddy, P. Surendra
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experimental part
p. 2823 - 2836
(2011/12/01)
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- Iron catalyst for oxidation in water: Surfactant-type iron complex-catalyzed mild and efficient oxidation of aryl alkanes using aqueous TBHP as oxidant in water
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Surfactant-type iron(III) complex, Fe2O(DS)4, was found to be effective for benzylic oxidation of simple aryl alkanes using aqueous t-butyl hydroperoxide (TBHP) as an oxidant. Copyright
- Nagano, Takashi,Kobayashi, Shu
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supporting information; experimental part
p. 1042 - 1043
(2009/12/02)
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- Nickel-catalyzed cross-coupling reactions of aryltitanium(IV) alkoxides with aryl halides
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A nickel-catalyzed cross-coupling reaction between aryltitanium(IV) alkoxides and various functionalized aryl halides is described. The reaction requires Ni(acac)2 (0.5 mol%), a phosphine or an N-heterocyclic carbene ligand (NHC ligand; 0.5-1.0 mol%) and proceeds at 25°C within 1-24 hours. Georg Thieme Verlag Stuttgart.
- Manolikakes, Georg,Dastbaravardeh, Navid,Knochel, Paul
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p. 2077 - 2080
(2008/02/09)
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- 5-Phenyl substituted 1-methyl-2-pyridones and 4′-substituted biphenyl-4-carboxylic acids. synthesis and evaluation as inhibitors of steroid-5α-reductase type 1 and 2
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The synthesis of a series of 5-phenyl substituted 1-methyl-2-pyridones (I) and 4′-substituted biphenyl-4-carboxylic acids (II) as novel A-C ring steroidomimetic inhibitors of 5α-reductase (5αR) is described. Compounds 1-4 (I) were synthesized by palladium catalyzed cross coupling (Ishikura) reaction between diethyl(3-pyridyl)borane and aryl halides (1b-4b) followed by α-oxidation with sodium ferrocyanate of the 1-methyl-pyridinium salt. Inhibitors II (5-18) were obtained either by two successive Friedel-Crafts acylations from biphenyl (5a-10a) followed by saponification to yield the corresponding carboxylic acids (5-10) or by Suzuki cross coupling reaction to give the 4′-substituted biphenyl 1-4-carbaldehydes 11a-18a. The latter compounds were subjected to a Lindgren oxidation to yield compounds 11-18. The compounds were tested for inhibitory activity toward human and rat 5 αR1 and 2. The test compounds inhibited 5αR, showing a broad range of inhibitory potencies. The best compound in series I was the N-(dicyclohexyl)-4-(1,2-dihydro-1-methyl-2-oxopyrid-5-yl) benzamide 4 exhibiting an IC50 value for the human type 2 enzyme of 10 μM. In series II, the most active compound toward human type 2 isozyme was the 4′-(dicyclohexyl)acetyl-4-biphenyl carboxylic acid (10; IC50 = 220 nM). Both series showed only marginal activity toward the human type 1 isozyme. In conclusion, the biphenyl carboxylic acids (II) are more appropiate for 5αR inhibition than the 5-phenyl-1-methyl-2-pyridones (1). Especially the 4′-carbonyl compounds 5-10 represent new lead structures for the development of novel human type 2 inhibitors. Copyright
- Picard, Franck,Schulz, Tobias,Hartmann, Rolf W.
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p. 437 - 448
(2007/10/03)
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- Sulfonylated aminothiazoles as new small molecule inhibitors of protein phosphatases
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Based on a previously identified lead structure, SC-ααδ9, we have developed a versatile new chemical scaffold that can be readily modified to generate libraries of both Tyr and dual specificity phosphatase inhibitors with reduced molecular weight and lipophilicity. The most potent analogue identified to date, aminothiazole 8z, inhibits the dual specificity phosphatase Cdc25B with a Ki of 4.6 ± 0.4 μM and a Hill coefficient of 2.
- Wipf, Peter,Aslan, Diana C.,Southwick, Eileen C.,Lazo, John S.
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p. 313 - 317
(2007/10/03)
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- Versatile palladium-catalyzed arylation of organomanganese chlorides by aryl bromides
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In THF, a palladium-catalyzed cross-coupling reaction of organomanganese reagents with various aryl bromides including unreactive deactivated or hindered aryl bromides was performed successfully in the presence of a new catalytic system 1% PdCl2(dppp)-four equivalents DME. The scope of the reaction is very broad since many functional groups are tolerated, moreover, even hindered O,O′-di- or trisubstituted diaryls were obtained in high yields. It is interesting to note that hindered aryl bromides are more reactive than the corresponding aryl iodides. Alkyl, alkenyl and alkynylmanganese chlorides also react under similar conditions.
- Riguet, Eric,Alami, Mouad,Cahiez, Gérard
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p. 376 - 379
(2007/10/03)
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- Synthesis of Isocyano and (Haloalkynyl)Biphenyls: New Thermotropic Liquid Crystals
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4-n-Alkyl-4'-cyanobiphenyls (1) have achieved widespread application as stable thermotropic liquid crystals with mesophases at room temperature.The importance of the cyano group in the liquid-crystalline behaviour of these compounds is not clearly defined.By modifying this functional group with minimal changes in molecular geometry, we have found two new classes of mesomorphs, 4-n-Alkyl-4'-isocyanobiphenyls (2) and 4-n-alkyl-4'-(haloalkynyl)biphenyls (3).The synthesis of these compounds is described.Compound 2a (R = n-butyl) is non-mesomorphic, whereas compound 2b (R = n-pentyl) is a virtual liquid crystal melting at 34-5 deg C and supercooling to a nematic phase at 30 deg C, and 2c (R = n-hexyl) is a nematic liquid crystal from 9 to 19 deg C.Compounds of structure 3 (R = n-pentyl, X = Si(CH3)3, H, CH3, Cl) are not liquid crystals.The corresponding bromo- and iodoalkynes (3, R = n-pentyl, S = Br, I) are liquid crystals with mesomorphic ranges of 88-108 deg C and 110-119 deg C, respectively.
- Bailey, A. L.,Bates, Gordon S.
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p. 417 - 428
(2007/10/02)
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- SYNTHESIS OF 4-ALKYL-4'-CYANOBIPHENYLS
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Liquid crystals of the 4-alkyl-4'-cyanobiphenyl group were synthesized without the use of copper cyanide. 4-Alkyl-4'-formylbiphenyls and the 4-formyloximes of 4'-alkylbiphenyl, which possess a liquid-crystalline state, were isolated.Beginning with the pentyl homolog, they form an enantiotropic nematic phase, and beginning with octyl homolog they also form a smectic meso phase.
- Ruolene, Yu. I.,Adomenas, P. V.,Sirutkaitis, R. A.,Denis, G. I.
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p. 1187 - 1191
(2007/10/02)
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- NEW SIMPLE METHOD FOR OBTAINING 4-n-ALKYL-4 prime -CYANOBIPHENYLS.
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A new method is described of obtaining 4-n-alkyl-4 prime -cyanobiphenyls from biphenyl. First biphenyl is acrylated and the resulting ketone is reduced in conditions of the Huang-Minlon reaction; next the obtained 4-n-alkylbiphenyl is converted to 4-n-alkyl-4 prime -iodobiphenyl which readily reacts with copper cyanide giving the required nitrile with a good yield.
- Dabrowski,Witkiewicz,Kenig
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p. 251 - 259
(2007/10/02)
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