- Synthesis and thermal, optical, and mechanical properties of sequence-controlled poly(1-adamantyl acrylate)-block-poly(n-butyl acrylate) containing polar side group
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We prepared the sequence-controlled block copolymers including poly(1-adamantyl acrylate) (PAdA) and poly(n-butyl acrylate) sequences as the hard and soft segments, respectively, by the organotellurium-mediated living radical polymerization. The thermal,
- Nakano, Yoshinori,Sato, Eriko,Matsumoto, Akikazu
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- Synthesis and biological evaluation of novel 5-hydroxylaminoisoxazole derivatives as lipoxygenase inhibitors and metabolism enhancing agents
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A versatile synthesis of novel 5-hydroxylaminoisoxazoles bearing adamantane moieties has been accomplished using the heterocyclization reactions of readily available unsaturated esters by the treatment with tetranitromethane in the presence of triethylami
- Averina, Elena B.,Vasilenko, Dmitry A.,Gracheva, Yulia A.,Grishin, Yuri K.,Radchenko, Eugene V.,Burmistrov, Vladimir V.,Butov, Gennady M.,Neganova, Margarita E.,Serkova, Tatyana P.,Redkozubova, Olga M.,Shevtsova, Elena F.,Milaeva, Elena R.,Kuznetsova, Tamara S.,Zefirov, Nikolay S.
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- Synthesis of organic-inorganic polymer hybrids by means of host-guest interaction utilizing cyclodextrin
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Organic -inorganic polymer hybrids were synthesized utilizing the host-guest interaction. Cyclodextrins (CDs, α-, β-, γ-CD) could be dispersed in the silica gel matrix at a nanometer level because of the hydrogen-bonding interaction between hydroxyl moieties of CD and residual silanol groups of silica gel. It is known that β-CD forms a strong host-guest complex with l-adamantanol in an aqueous solution. Thus, the organic polymer modified with an adamantane group at the side chain (ADA-PAA) and silica gel hybrids could be prepared by complexation of β-CD with ADA-PAA. β-CD played a role as a compatibilizer between ADA-PAA and silica gel to obtain transparent and homogeneous polymer hybrids. The evidence of the host-guest complex formation was confirmed by a fluorescence technique using a dansyl group. Furthermore, transparent and homogeneous CD-polymer complex/silica gel hybrids were prepared utilizing CDs formed polyrotaxane-type inclusion complexes with polymers, such as poly(ethylene glycol) and polyisobutylene.
- Ogoshi, Tomoki,Chujo, Yoshiki
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- Tautomycetin Synthetic Analogues: Selective Inhibitors of Protein Phosphatase I
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Ser/Thr protein phosphatases (PPs) regulate a substantial range of cellular processes with protein phosphatases 1 (PP1) and 2 A (PP2A) accounting for over 90 % of the activity within cells. Nevertheless, tools to study PPs are limited as PPs inhibitors, particularly those selective for PP1 inhibition, are relatively scarce. Two examples of PP1-selective inhibitors, which share structural similarities, are tautomycin (TTM) and tautomycetin (TTN). This work describes the development of PP1/PP2A inhibitors that incorporate key structural features of TTM and TTN and are designed to conserve regions known to bind the active site of PP1/PP2A but vary regions that differentially contact the hydrophobic groove of PP1/PP2A. In all 28 TTN analogues were synthetically generated that inhibit PP1/PP2A activity at 50 values were determined for the seven most active analogues, which ranged from 34 to 1500 nM (PP1) and 70 to 6800 nM (PP2A). Four of the seven analogues possessed PP1 selectivity, and one demonstrated eightfold selectivity in the nanomolar range (PP1 IC50=34 nM, PP2A IC50=270 nM). A rationale is given for the observed differences in selectivity.
- Woydziak, Zachary R.,Yucel, A. John,Chamberlin, A. Richard
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p. 839 - 850
(2020/12/15)
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- Activated Self-Resolution and Error-Correction in Catalytic Reaction Networks**
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Understanding the emergence of function in complex reaction networks is a primary goal of systems chemistry and origin-of-life studies. Especially challenging is to create systems that simultaneously exhibit several emergent functions that can be independently tuned. In this work, a multifunctional complex reaction network of nucleophilic small molecule catalysts for the Morita-Baylis-Hillman (MBH) reaction is demonstrated. The dynamic system exhibited triggered self-resolution, preferentially amplifying a specific catalyst/product set out of a many potential alternatives. By utilizing selective reversibility of the products of the reaction set, systemic thermodynamically driven error-correction could also be introduced. To achieve this, a dynamic covalent MBH reaction based on adducts with internal H-transfer capabilities was developed. By careful tuning of the substituents, rate accelerations of retro-MBH reactions of up to four orders of magnitude could be obtained. This study thus demonstrates how efficient self-sorting of catalytic systems can be achieved through an interplay of several complex emergent functionalities.
- Schaufelberger, Fredrik,Ramstr?m, Olof
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supporting information
p. 10335 - 10340
(2021/05/07)
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- Acid- And base-switched palladium-catalyzed γ-C(sp3)-H alkylation and alkenylation of neopentylamine
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The functionalization of remote unactivated C(sp3)-H and the reaction selectivity are among the core pursuits for transition-metal catalytic system development. Herein, we report Pd-catalyzed γ-C(sp3)-H-selective alkylation and alkenylation with removable 7-azaindole as a directing group. Acid and base were found to be the decisive regulators for the selective alkylation and alkenylation, respectively, on the same single substrate under otherwise the same reaction conditions. Various acrylates were compatible for the formation of C(sp3)-C(sp3) and C(sp3)-C(sp2) bonds. The alkenylation protocol could be further extended to acrylates with natural product units and α,β-unsaturated ketones. The preliminary synthetic manipulation of the alkylation and alkenylation products demonstrates the potential of this strategy for structurally diverse aliphatic chain extension and functionalization. Mechanistic experimental studies showed that the acidic and basic catalytic transformations shared the same six-membered dimer palladacycle.
- Zhang, Jinquan,Zhang, Shuaizhong,Zou, Hongbin
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supporting information
p. 3466 - 3471
(2021/05/31)
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- Phosphine-Catalyzed Cascade Annulation of MBH Carbonates and Diazenes: Synthesis of Hexahydrocyclopenta[c]pyrazole Derivatives
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A phosphine-catalyzed cascade annulation of Morita-Baylis-Hillman (MBH) carbonates and diazenes was achieved, giving tetrahydropyrazole-fused heterocycles bearing two five-membered rings in moderate to excellent yields. The reaction underwent an unprecedented reaction mode of MBH carbonates, in which two molecules of MBH carbonates were fully merged into the ring system.
- Guo, Hongchao,Li, Hongxiang,Liu, Hao,Shi, Wangyu,Wang, Chang,Wang, Wei,Wu, Yongjun
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supporting information
p. 5571 - 5575
(2021/07/31)
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- Tick-borne flavivirus reproduction inhibitors based on isoxazole core linked with adamantane
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Infections caused by flaviviruses pose a huge threat for public health all over the world. The search for therapeutically relevant compounds targeting tick-borne flaviviruses requires the exploration of novel chemotypes. In the present work a large series
- Vasilenko, Dmitry A.,Dueva, Evgenia V.,Kozlovskaya, Liubov I.,Zefirov, Nikolay A.,Grishin, Yuri K.,Butov, Gennady M.,Palyulin, Vladimir A.,Kuznetsova, Tamara S.,Karganova, Galina G.,Zefirova, Olga N.,Osolodkin, Dmitry I.,Averina, Elena B.
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p. 629 - 637
(2019/04/04)
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- Method for synthesis of 1-adamantyl esters of unsaturated acids
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New method for synthesis of adamantyl esters of acrylic, methacrylic, and cinnamic acids was developed. The reactions carried out under mild conditions in the absence of catalysts provide a high yield. Pleiades Publishing, Ltd., 2012.
- Butov,Pastukhova,Kamneva,Saad
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p. 1590 - 1591
(2013/02/23)
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- Engineering reactions in crystalline solids: Photochemical generation of secondary and tertiary enol radical pairs from crystalline ketodiesters
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The photochemical decarbonylation of several crystalline 1,3-acetonedicarboxylates has been analyzed in solution and in the solid state. It is shown that the efficiency of the solid-state reaction depends on the stability of the intermediate acyl-alkyl an
- Yang,Ng,Garcia-Garibay
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p. 4468 - 4475
(2007/10/03)
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- Hypervalent (tert-butylperoxy)iodanes generate iodine-centered radicals at room temperature in solution: Oxidation and deprotection of benzyl and allyl ethers, and evidence for generation of α-oxy carbon radicals
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1-(tert-Butylperoxy)-1,2-benziodoxol-3(1H)-one (1a) oxidizes benzyl and allyl ethers to the esters at room temperature in benzene or cyclohexane in the presence of alkali metal carbonates. Since this reaction is compatible with other protecting groups such as MOM, THP, and TBDMS ethers, and acetoxy groups, and because esters are readily hydrolyzed under basic conditions, this new method provides a convenient and effective alternative to the usual reductive deprotection. Oxidation with 1a occurs readily with C-H bonds activated by both enthalpic effects (benzylic, allylic, and propargylic C-H bonds) and/or polar effects (α-oxy C-H bonds), generating α-oxy carbon-centered radicals, which can be detected by nitroxyl radical trapping. Measurement of the relative rates of oxidation for a series of ring-substituted benzyl n-butyl ethers 2d and 2p-s indicated that electron-releasing groups such as p-MeO and p-Me groups increase the rate of oxidation, and Hammett correlation of the relative rate factors with the σ+ constants of substituents afforded the reaction constant ρ+ = -0.30. The large value of the isotope effect obtained for the oxidation of benzyl n-butyl ether 2d (k(H)/k(D) = 12-14) indicates that the rate-determining step of the reactions probably involves a high degree of benzylic C-H bond breaking. The effects of molecular dioxygen were examined, and the mechanism involving the intermediacy of the tert-butylperoxy acetal 5 and/or the hydroperoxy acetal 32 is proposed. Particularly noteworthy is the finding that (tert-butylperoxy)iodane 1a can generate the tert-butylperoxy radical and the iodine-centered radical 33a, even at room temperature in solution, via homolytic bond cleavage of the hypervalent iodine(III)-peroxy bond.
- Ochiai, Masahito,Ito, Takao,Takahashi, Hideo,Nakanishi, Akinobu,Toyonari, Mika,Sueda, Takuya,Goto, Satoru,Shiro, Motoo
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p. 7716 - 7730
(2007/10/03)
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- Synthesis of Thermally Stable Vinyl Polymers from Adamantyl-Containing Acrylic Derivatives
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1-Adamantyl and 3,5-dimethyl-1-adamantyl acrylates, methacrylates, and crotonates were polymerized through radical or anionic mechanism.Thermally stable and less-flexible vinyl polymers were obtained, depending on the structure of the repeating monomer units.
- Otsu, Takayuki,Matsumoto, Akikazu,Horie, Atsushi,Tanaka, Satoshi
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p. 1145 - 1148
(2007/10/02)
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