- Liquid Organic Frameworks: The Single-Network "plumber's Nightmare" Bicontinuous Cubic Liquid Crystal
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Novel bolapolyphiles, built of a p-terphenyl or bistolane core with polar glycerol end-groups and two laterally attached n-alkyl or semiperfluoroalkyl chains, form the first "single plumber's nightmare network", the simplest soft-matter cubic phase (Pm3?
- Chen, Changlong,Cheng, Xiaohong,Liu, Feng,Poppe, Silvio,Tschierske, Carsten,Ungar, Goran,Zeng, Xiangbing,Zhang, Rui-Bin
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- Aminoalkyl radicals as halogen-atom transfer agents for activation of alkyl and aryl halides
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Organic halides are important building blocks in synthesis, but their use in (photo)redox chemistry is limited by their low reduction potentials. Halogen-atom transfer remains the most reliable approach to exploit these substrates in radical processes despite its requirement for hazardous reagents and initiators such as tributyltin hydride. In this study, we demonstrate that a-aminoalkyl radicals, easily accessible from simple amines, promote the homolytic activation of carbon-halogen bonds with a reactivity profile mirroring that of classical tin radicals. This strategy conveniently engages alkyl and aryl halides in a wide range of redox transformations to construct sp3-sp3, sp3-sp2, and sp2-sp2 carbon-carbon bonds under mild conditions with high chemoselectivity.
- Constantin, Timothée,Juliá, Fabio,Leonori, Daniele,Regni, Alessio,Sheikh, Nadeem S.,Zanini, Margherita
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p. 1021 - 1026
(2020/03/10)
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- Preparation of Polyfunctional Arylzinc Organometallics in Toluene by Halogen/Zinc Exchange Reactions
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A wide range of polyfunctional diaryl- and diheteroarylzinc species were prepared in toluene within 10 min to 5 h through an I/Zn or Br/Zn exchange reaction using bimetallic reagents of the general formula R′2Zn?2 LiOR (R′=sBu, tBu, pTol). Highly sensitive functional groups, such as a triazine, a ketone, an aldehyde, or a nitro group, were tolerated in these exchange reactions, enabling the synthesis of a plethora of functionalized (hetero)arenes after quenching with various electrophiles. Insight into the constitution and reactivity of these bimetallic mixtures revealed the formation of highly active lithium diorganodialkoxyzincates of type [R′2Zn(OR)2Li2].
- Balkenhohl, Moritz,Ziegler, Dorothée S.,Desaintjean, Alexandre,Bole, Leonie J.,Kennedy, Alan R.,Hevia, Eva,Knochel, Paul
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supporting information
p. 12898 - 12902
(2019/07/31)
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- Carbonylative Transformation of Allylarenes with CO Surrogates: Tunable Synthesis of 4-Arylbutanoic Acids, 2-Arylbutanoic Acids, and 4-Arylbutanals
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In this Communication, procedures for the selective synthesis of 4-arylbutanoic acids, 2-arylbutanoic acids, and 4-arylbutanals from the same allylbenzenes have been developed. With formic acid or TFBen as the CO surrogate, reactions proceed selectively and effectively under carbon monoxide gas-free conditions.
- Wu, Fu-Peng,Li, Da,Peng, Jin-Bao,Wu, Xiao-Feng
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supporting information
p. 5699 - 5703
(2019/08/01)
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- Palladium-Catalyzed meta-C-H Olefination of Arene-Tethered Diols Directed by Well-Designed Pyrimidine-Based Group
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The palladium-catalyzed meta-olefination of arene-tethered diols attached to a well-designed pyrimidine moiety is presented. Applications of the protocol are illustrated by the synthesis of various diol-based natural products, such as coumarins, phenylpropanoids, stilbenes, and chalcones. Advantages of this method are demonstrated through the easy removal of the template and a gram-scale olefination reaction. Finally, experimental verification, including 1H NMR, ESI-MS and IR, and DFT studies are undertaken to elucidate the mechanistic complexity.
- Fang, Siqiang,Wang, Xiaobing,Yin, Fucheng,Cai, Pei,Yang, Huali,Kong, Lingyi
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supporting information
(2019/03/19)
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- Palladium-Catalyzed Oxidative Allylation of Sulfoxonium Ylides: Regioselective Synthesis of Conjugated Dienones
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The first examples of palladium-catalyzed allylic C-H oxidative allylation of sulfoxonium ylides to afford the corresponding conjugated dienones with moderate to good yields have been established. The features of this novel conversion include mild reaction conditions, wide substrate scope, and excellent regioselectivity.
- Li, Chunsheng,Li, Meng,Zhong, Wentao,Jin, Yangbin,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 872 - 875
(2019/05/16)
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- Structure–activity relationships and docking studies of hydroxychavicol and its analogs as xanthine oxidase inhibitors
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Hydroxychavicol (HC), which is obtained from the leaves of Piper betle LINN. (Piperaceae), inhibits xanthine oxidase (XO) with an IC50 value of 16.7μM, making it more potent than the clinically used allopurinol (IC50=30.7μM). Herein, a structure–activity relationship analysis of the polar part analogs of HC was conducted and an inhibitor was discovered with a potency 13 times that of HC. Kinetic studies have revealed that HC and its active analog inhibit XO in an uncompetitive manner. The binding structure prediction of these inhibitor molecules to the XO complex with xanthine suggested that both compounds (HC and its analog) could simultaneously form hydrogen bonds with xanthine and XO.
- Nishiwaki, Keiji,Ohigashi, Kanae,Deguchi, Takahiro,Murata, Kazuya,Nakamura, Shinya,Matsuda, Hideaki,Nakanishi, Isao
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p. 741 - 747
(2018/07/05)
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- TRICYCLIC COMPOUND AND USE THEREOF
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The present invention relates to: a compound selected from the group consisting of a tricyclic compound having the structure of formula I, a pharmaceutically acceptable salt, an isomer, a solvate and a precursor thereof; and a use thereof. The compound effectively controls GPR40, and thus, can be effectively used for the prophylaxis or treatment of diseases associated with GPR40, for example, diabetes and many other diseases.
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Paragraph 1633; 1634; 1635
(2016/01/25)
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- Cyclohexanones by Rh-mediated intramolecular C-H insertion
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Some long chain α-aryl α-diazo ketones under Rh catalysis cyclize efficiently to the corresponding cyclohexanones. This is in marked contrast to the cyclizations of α-diazo β-ketoesters, which consistently deliver cyclopentanone products.
- Taber, Douglass F.,Paquette, Craig M.,Gu, Peiming,Tian, Weiwei
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p. 9772 - 9780
(2013/10/22)
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- Nickel-catalyzed heck-type reactions of benzyl chlorides and simple olefins
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Nickel-catalyzed intermolecular benzylation and heterobenzylation of unactivated alkenes to provide functionalized allylbenzene derivatives are described. A wide range of both the benzyl chloride and alkene coupling partners are tolerated. In contrast to analogous palladium-catalyzed variants of this process, all reactions described herein employ electronically unbiased aliphatic olefins (including ethylene), proceed at room temperature, and provide 1,1-disubstituted olefins over the more commonly observed 1,2-disubstituted olefins with very high selectivity.
- Matsubara, Ryosuke,Gutierrez, Alicia C.,Jamison, Timothy F.
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supporting information; experimental part
p. 19020 - 19023
(2011/12/21)
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- The attempted stereoselective synthesis of chiral 2,2′-biindoline
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The attempted first stereoselective synthesis of 2,2′-biindoline using a metathesis-Sharpless asymmetric dihydroxylation strategy results in the synthesis of the heterocycle in poor to modest stereoselectivity. Attempts to improve the ee by varying the he
- Gresser, Mary J.,Wales, Steven M.,Keller, Paul A.
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experimental part
p. 6965 - 6976
(2010/09/18)
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- Efficient double bond migration of allylbenzenes catalyzed by Pd(OAc) 2-HFIP system with unique substituent effect
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A novel catalyst system of Pd(OAc)2-HFIP induces double-bond migration of allylbenzenes under mild conditions with low catalytic loading to afford 1-propenylbenzenes. The reaction shows a unique substituent effect that is highly dependent on the distance of substituents from the allylic moiety. Thus, the reactivity of substrates bearing a methyl group is ordered in para > meta > ortho, whereas it is entirely reversed as ortho > meta > para for methoxy and chloro substituents.
- Nishiwaki, Nagatoshi,Kamimura, Ryuichiro,Shono, Kimihiro,Kawakami, Toshihiko,Nakayama, Katsuhisa,Nishino, Kohei,Nakayama, Takayuki,Takahashi, Keisuke,Nakamura, Aki,Hosokawa, Takahiro
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supporting information; experimental part
p. 3590 - 3592
(2010/08/19)
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- Palladium-catalyzed cross-coupling reactions of potassium alkenyltrifluoroborates with organic halides in aqueous media
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Potassium vinyl and alkenyltrifluoroborates are cross-coupled with aryl and heteroaryl bromides using 1 mol % Pd loading of 4-hydroxyacetophenone oxime derived palladacycle or Pd(OAc)2 as precatalysts, K 2CO3 as base, and TBAB as additive and water reflux under conventional or microwave heating to afford styrenes, stilbenoids, and alkenylbenzenes. These borates can be cross-coupled diastereoselectively with allyl and benzyl chlorides using KOH as base in acetone-water (3:2) at 50°C and 0.1 mol % Pd loading, giving the corresponding 1,4-dienes and allylarenes, respectively. These simple phosphine-free reaction conditions allow the palladium recycling from the aqueous phase during up to five runs by extractive separation of the products, which contain 58-105 ppm of Pd.
- Alacid, Emilio,Najera, Carmen
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supporting information; experimental part
p. 2321 - 2327
(2009/07/18)
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- ASPARTYL PROTEASE INHIBITORS
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The invention provides compounds of the formula (I) N-oxides, addition salts, quaternary amines, metal complexes, stereochemically isomeric forms and metabolites thereof, wherein G is-O-, -S(=O)r-, -CRdRd or -NRa-; W is H, C1-C6
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Page/Page column 43
(2009/01/20)
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- One-pot synthesis of bicyclic β-alkoxy amides from cyanohydrin ethers
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In this manuscript we report that Intramolecular Friedel-Crafts alkylation reactions of aryl-substituted a-alkoxy acylimines proceed in the presence of mild Lewis acids to afford bicyclic β-alkoxy amides. The intermediate acylimines are prepared through c
- Xiao, Qing,Floreancig, Paul E.
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supporting information; experimental part
p. 1139 - 1142
(2009/04/06)
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- Xantphos as an efficient ligand for palladium-catalyzed cross-coupling reactions of aryl bromides and triflates with allyl acetates and indium
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(Chemical Equation Presented) Xantphos was found to be an efficient ligand for palladium-catalyzed allyl cross-coupling reactions of aryl bromides and triflates with allylindium reagents generated in situ from allyl acetates and indium. These reactions occur in high yield with good functional group tolerance.
- Seomoon, Dong,Phil, Ho Lee
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p. 1165 - 1168
(2008/09/18)
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- Inter- and intramolecular palladium-catalyzed allyl cross-coupling reactions using allylindium generated in situ from allyl acetates, indium, and indium trichloride
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Inter- and intramolecular palladium-catalyzed ally! cross-coupling reactions using allylindium generated in situ by treatment of allyl acetates with indium and indium trichloride in the presence of Pd0 catalyst and nBuNMe2 in DMF were successfully demonstrated. Allylindium species generated in situ by reductive transmetalation of π- allylpalladium(II) complexes, obtained from a variety of allyl acetales in the presence of Pd0 catalyst together with indium and indium trichloride, were found to be capable of acting as effective nucleophilic coupling partners in Pd-catalyzed cross-coupling reactions. A variety of allyl acetates such as but-l-en-3-yl acetate, crotyl acetate, and 2-methylallyl acetate afforded the corresponding allylic compounds in good yields in cross-coupling reactions. Various electrophilic cross-coupling partners such as aryl iodides and vinyl bromides and triflates participate in these reactions. Not only intermolecular but also intramolecular Pd-catalyzed cross-coupling reactions work equally well to produce the desired allylic coupling products in good yields.
- Seomoon, Dong,Lee, Kooyeon,Kim, Hyunseok,Lee, Phil Ho
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p. 5197 - 5206
(2008/02/10)
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- The synthesis of phenolic propane-1, 2- and 1,3-diols as intermediates in immobilised chelatants for the borate anion
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The isomeric 3-(hydroxyphenyl)propane-1, 2-diols have been synthesised from allylic precursors by epoxidation and cleavage. Several different methods have been examined for obtaining 1-(methoxyphenyl)propane-1, 3-diols. 2-(methoxyphenyl)propane-1, 3-diols and certain hydroxy analogues have been obtained from benzaldoximes converted by oxidation to methoxy- and benzyloxynitromethylbenzenes followed by hydroxymethylation with formaldehyde and catalytic hydrogenation.
- Tyman, John H. P.,Payne
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p. 691 - 695
(2007/10/03)
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- A simple synthetic approach to allylated aromatics via the Suzuki-Miyaura cross-coupling reaction
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The Pd-catalyzed cross-coupling reaction of aromatic iodides and bromides with allylboronic acid esters (2a,b) in the presence of CsF gave allylated aromatics. Georg Thieme Verlag Stuttgart.
- Kotha, Sambasivarao,Behera, Manoranjan,Shah, Vrajesh R.
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p. 1877 - 1880
(2007/10/03)
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- Nickel-catalyzed cross-coupling reaction of aryl halides with allylic zirconium reagents generated in situ from zirconocene(alkene) complexes
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Allylic zirconium reagents that are generated in situ via allylic C-H bond activation of alkenes proved to serve as metal counterparts in nickel-catalyzed cross-coupling reactions. Georg Thieme Verlag Stuttgart.
- Hirano, Koji,Fujita, Kazuya,Yorimitsu, Hideki,Oshima, Koichiro
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p. 1787 - 1788
(2007/10/03)
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- The reduction of aryl diethyl phosphate esters with lithium di-tert-butylbiphenylide radical anion: Aromatic hydrocarbons via the deoxygenation of phenols
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The reduction of aryl diethyl phosphate esters by lithium 4,4′-di-tert-butylbiphenylide (LiDTBB) in THF at 0 °C is described. The reactions can be carried out either stoichiometrically (3.0 equiv LiDTBB) or with only a catalytic amount of DTBB (0.25 equiv) in the presence of lithium (2.1-3.0 equiv) and the phosphate. Products are separated from DTBB by solubility differences, by acid/base vs. neutral extraction, or by flash chromatography.
- Lusch, Michael J.,Woller, Kevin R.,Keller, Anthony M.,Turk, Michael C.
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p. 551 - 554
(2007/10/03)
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- Cobalt-catalyzed cross-coupling reactions of alkyl halides with allylic and benzylic grignard reagents and their application to tandem radical cyclization/cross-coupling reactions
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Details of cobalt-catalyzed cross-coupling reactions of alkyl halides with allylic Grignard reagents are disclosed. A combination of cobalt(II) chloride and 1,2-bis(diphenylphosphino)ethane (DPPE) or 1,3-bis(diphenylphosphino)propane (DPPP) is suitable as a precatalyst and allows secondary and tertiary alkyl halides-as well as primary ones-to be employed as coupling partners for allyl Grignard reagents. The reaction offers a facile synthesis of quaternary carbon centers. which has practically never been possible with palladium, nickel, and copper catalysts. Benzyl, methallyl, and crotyl Grignard reagents can all couple with alkyl halides. The benzylation definitely requires DPPE or DPPP as a ligand. The reaction mechanism should include the generation of an alkyl radical from the parent alkyl halide. The mechanism can be interpreted in terms of a tandem radical cyclization/cross-coupling reaction. In addition, serendipitous tandem radical cyclization/cyclopropanation/carbonyl allylation of 5-alkoxy-6-halo-4-oxa-1-hexene derivatives is also described. The intermediacy of a carbon-centered radical results in the loss of the original stereochemistry of the parent alkyl halides, creating the potential for asymmetric cross-coupling of racemic alkyl halides.
- Ohmiya, Hirohisa,Tsuji, Takashi,Yorimitsu, Hideki,Oshima, Koichiro
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p. 5640 - 5648
(2007/10/03)
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- Palladium-indium-indium(III) chloride-mediated allyl cross-coupling reactions using allyl acetates
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Allylindiums in situ generated by reductive transmetalation of π-allylpalladium(II) complexes, obtained from allyl acetates and palladium(0) catalyst, with indium and indium(III) chloride are effective nucleophilic cross-coupling partners in Pd-catalyzed allyl cross-coupling reactions with a variety of electrophilic cross-coupling partners.
- Lee, Phil Ho,Seomoon, Dong,Lee, Kooyeon,Kim, Sundae,Kim, Hyunseok,Kim, Hyun,Shim, Eunkyong,Lee, Miae,Lee, Seokju,Kim, Misook,Sridhar, Madabhushi
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p. 1641 - 1645
(2007/10/03)
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- Stereospecific Pd(O)-Catalyzed Malonate Additions to Allylic Hydroxy Phosphonate Derivatives: A Formal Synthesis of (-)-Enterolactone
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A combination of cross-metathesis and malonate addition was applied to a formal synthesis of the mammalian lignan enterolactone 5. The cross-metathesis of alkene 6 and phosphonate 3a gave the substituted allylic phosphonate 3d. The palladium-catalyzed add
- Yan, Bingli,Spilling, Christopher D.
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p. 2859 - 2862
(2007/10/03)
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- Design, synthesis and cytotoxicity of 7-deoxy aryl discodermolide analogues
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A series of 7-deoxy discodermolide analogues in which the lactone fragment 'C' was replaced by aryl substituents were designed, synthesized, and evaluated for cytotoxicity.
- Burlingame, Mark A.,Shaw, Simon J.,Sundermann, Kurt F.,Zhang, Dan,Petryka, Joseph,Mendoza, Esteban,Liu, Fenghua,Myles, David C.,LaMarche, Matthew J.,Hirose, Tomoyasu,Freeze, B. Scott,Smith III, Amos B.
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p. 2335 - 2338
(2007/10/03)
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- Calamitic bolaamphiphiles with (semi)perfluorinated lateral chains: Polyphilic block molecules with new liquid crystalline phase structures
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Novel bolaamphiphiles consisting of a rigid biphenyl unit, two terminal polar 1,2-diol units and laterally attached (semi)perfluorinated chains have been synthesized via palladium-catalyzed cross coupling reactions as the key step. The thermotropic liquid
- Cheng, Xiaohong,Prehm, Marko,Das, Malay Kumar,Kain, Jens,Baumeister, Ute,Diele, Siegmar,Leine, Dag,Blume, Alfred,Tschierske, Carsten
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p. 10977 - 10996
(2007/10/03)
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- Reductions of aryl perfluorosulfonates with dimethylamine·borane (Me2NH·BH3) catalyzed by Pd(0): An operationally simple, inexpensive, and general protocol
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Treatment of aryl nonaflates or triflates in CH3CN in the presence of one equivalent of Me2NH·BH3 and K2CO3 leads via Pd(0) catalysis to high yields of reduced arenes.
- Lipshutz, Bruce H.,Buzard,Vivian, Randall W.
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p. 6871 - 6874
(2007/10/03)
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- Radiopharmaceutical agents for the detection of Alzheimer's disease
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Novel anticholinergics which are related to vesamicol are particularly useful when radiolabeled for evaluating cholinergic innervation in the living human brain. The cholinergic deficit in the Alzheimer's brain should be identifiable with these radioligan
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- Acyclic analogues of 2-(4-phenylpiperidino)cyclohexanol (vesamicol): Conformationally mobile inhibitors of vesicular acetylcholine transport
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Several 1,3-disubstituted propan-2-ols and one α,β-disubstituted ethanol (11i) were synthesized and evaluated as potential acyclic mimics of the vesicular acetylcholine transport inhibitor 2-(4-phenylpiperidinyl)cyclohexanol (1, vesamicol, AH5183). Analogues containing the 4-phenylpiperidyl fragment (11a, 11b) were more potent than those containing the 4-phenylpiperazyl moiety (11e, 11f). Substitution at the second terminal carbon of the propyl (or ethyl) fragment with simple lipophilic aryl substituents yielded potent inhibitors of vesicular acetylcholine storage, including (-)-11a and d-11i, which are equipotent with vesamicol. However, the activity of analogues containing bicyclic aryl groups was susceptible to aryl substitution patterns (11g vs 11h), indicating a definite receptor site topography. In addition, the inhibitory activity of these acyclic analogues was enantioselective, exhibiting a preference, similar to the parent vesamicol, for the levorotatory isomer [(-)-11a vs (+)-11a]. Therefore, the simple lipophilic acyclic vicinal amino alcohols may successfully mimic the biological activity of vesamicol.
- Efange,Michelson,Dutta,Parsons
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p. 2638 - 2643
(2007/10/02)
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