- Emergent Self-Assembly Pathways to Multidimensional Hierarchical Assemblies using a Hetero-Seeding Approach
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The controlled formation of complex and functional 1-, 2-, and 3D hierarchical assemblies from molecular building blocks represents a key current challenge. Herein, we report the use of a seeded growth approach for a series of perylenediimide-based molecules (PDIs 1–4) to access otherwise inaccessible self-assembly pathways that yield complex hierarchical structures. The key to the new approach is to use hetero-seeds which possess a different composition and morphology from that of the molecular building block. For example, a nanotube seed (from PDI 3) and a microribbon seed (from PDI 4) were found to initiate different self-assembly pathways for PDI 1, which normally assembles to yield nanocoils. This led to the formation of unprecedented 3D scroll-like and scarf-like hierarchical nanostructures, respectively. Also, the hetero-seeds from PDI 3 initiate hidden self-assembly pathways of PDI 2 to generate 1D tubular heterojunctions. Significantly, this new strategy offers new opportunities to create emergent and functional hierarchical and complex structures from small molecule precursors.
- Liu, Yin,Gong, Yanjun,Guo, Yongxian,Xiong, Wei,Zhang, Yifan,Zhao, Jincai,Che, Yanke,Manners, Ian
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supporting information
p. 13484 - 13490
(2019/10/28)
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- Kinetic Control of a Self-Assembly Pathway towards Hidden Chiral Microcoils
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Manipulating the self-assembly pathway is essentially important in the supramolecular synthesis of organic nano- and microarchitectures. Herein, we design a series of photoisomerizable chiral molecules, and realize precise control over pathway complexity with external light stimuli. The hidden single-handed microcoils, rather than the straight microribbons through spontaneous assembly, are obtained through a kinetically controlled pathway. The competition between molecular interactions in metastable photostationary intermediates gives rise to a variety of molecular packing and thereby the possibility of chirality transfer from molecules to supramolecular assemblies.
- Guo, Yongxian,Liu, Yin,Gong, Yanjun,Xiong, Wei,Zhang, Chuang,Zhao, Jincai,Che, Yanke
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supporting information
p. 7463 - 7468
(2019/05/16)
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- New method for synthesis of EZH2 methyltransferase inhibitor GSK126
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GSK126 is a potent small-molecule inhibitor of S-adenosyl-methionine-competitive EZH2 methyltransferase and has the potential to be used clinically for preventing unwanted histone methylation of tumor suppressor genes. In this article, we describe a new s
- Lu, Chen,Zhang, Qiang,Chen, Xin
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supporting information
p. 1215 - 1222
(2016/08/05)
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- Highly fluorescent one-handed nanotubes assembled from a chiral asymmetric perylene diimide
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Highly fluorescent bilayer nanotubes with a right- or left-handed helical sense were assembled from a chiral asymmetric perylene diimide for the first time, which constitute a new family member of self-assembled organic nanotubes.
- Ma, Xiaojie,Zhang, Yibin,Zheng, Yingxuan,Zhang, Yifan,Tao, Xia,Che, Yanke,Zhao, Jincai
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supporting information
p. 4231 - 4233
(2015/03/18)
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- Synthesis of optically active regioregular polythiophenes and their self-organization at the air-water interface
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Regioregular polythiophenes containing an optically active substituent in the third position of the thiophene ring, head-to-tail poly(3-[2-((S)-1- methyloctyloxy)ethyl]thiophene)s (HT-P(S)MOETs), were synthesized using highly reactive zinc. For comparison
- Takeoka, Yuko,Saito, Fumihiko,Rikukawa, Masahiro
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p. 8718 - 8727
(2013/07/26)
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- Molecular tectonics: Homochiral 3D cuboid coordination networks based on enantiomerically pure organic tectons and ZnSiF6
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Upon combining enantiomerically pure bis-monodentate organic tectons with ZnSiF6, homochiral 3D cuboid architectures displaying chiral channels are formed.
- Larpent, Patrick,Jouaiti, Abdelaziz,Kyritsakas, Nathalie,Hosseini, Mir Wais
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supporting information
p. 4468 - 4470
(2013/06/04)
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- Synthesis of four stereoisomers of (S)-2-methylpent-3-yl 3,13-dimethylpentadecanoate, a sex pheromone of the bagworm moth clania variegate, using stereospecific inversion of secondary sulfonates as a key step
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Females of some lepidopteran species produce novel sex pheromones with a methyl-branched structure, such as 2-methylpent-3-yl 3,13-dimethylpentadecanoate secreted by the bagworm moth Clania variegate. Recently, we have established a simple preparative method for the synthesis of methyl-branched building blocks by utilizing an SN2 reaction of chiral secondary tosylates derived from (S)- and (R)-propylene oxides. The usefulness of these building blocks was demonstrated by their application in the synthesis of all four stereoisomers of an acid moiety in the bagworm pheromone. The enantiomeric purities of all building blocks were confirmed by enantioselective HPLC analysis. We found that a secondary mesylate was superior to the corresponding tosylate because it avoided an elimination side reaction, and racemization in the SN2 reaction was not observed even at high temperature (150 °C). Finally, each optically active acid was esterified with (S)-2-methyl-3-pentanol, which was synthesized by a new route starting from (S)-valine. A simple route to methyl-branched building blocks has been developed by utilizing an S N2 reaction of chiral secondary sulfonates derived from (S)- and (R)-propylene oxides. The usefulness of these building blocks was demonstrated by the stereospecific synthesis of all four stereoisomers of a bagworm pheromone. Copyright
- Taguri, Tomonori,Yamamoto, Masanobu,Fujii, Toru,Muraki, Yuta,Ando, Tetsu
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p. 6924 - 6933
(2013/11/06)
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- Impact of absolute stereochemistry on the antiangiogenic and antifungal activities of itraconazole
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Itraconazole is used clinically as an antifungal agent and has recently been shown to possess antiangiogenic acitivity. Itraconazole has three chiral centers that give rise to eight stereoisomers. The complete role of stereochemistry in the two activities of itraconazole, however, has not been addressed adequately. For the first time, all eight stereoisomers of itraconazole (1a?h) have been synthesized and evaluated for activity against human endothelial cell proliferation and for antifungal activity against five fungal strains. Distinct antiangiogenic and antifungal activity profiles of the trans stereoisomers, especially 1e and 1f, suggest different molecular mechanisms underlying the antiangiogenic and antifungal activities of itraconazole.
- Shi, Wei,Nacev, Benjamin A.,Bhat, Shridhar,Liu, Jun O.
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scheme or table
p. 155 - 159
(2010/10/19)
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- Itraconazole and saperconazole stereoisomers
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The present invention is concerned with the stereoisomeric forms of itraconazole (X=Cl) and saperconazole (X=F), which may be represented by the formula and the pharmaceutically acceptable acid addition salt forms thereof, processes for preparing said stereoisomeric forms, the complexes thereof with cyclodextrin derivatives, pharmaceutical compositions comprising said complexes and methods of preparing said complexes and pharmaceutical compositions.
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- Synthesis and structure of poly(phenyl isocyanate)s bearing an optically active alkoxyl group
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Novel optically active phenyl isocyanate derivatives (1-6) bearing an (R)-sec-butoxy, (S)-2-methylbutoxy or (S)-3,7-dimethyloctyloxy group at the meta or para position on the phenyl ring were prepared and polymerized with an anionic initiator in tetrahydrofuran (THF). The resulting polymers from 1, 2, 4 and 6 showed much greater specific rotation than that of the corresponding monomers and an intense circular dichroism (CD) band in the main-chain absorption region, indicating that these polymers have a predominantly one-handed helical conformation in solution. On the other hand, the polymers obtained from 3 and 5 showed a much smaller specific rotation than that of the above polymers at room temperature. The polymers from 2 and 5 showed a remarkable change in optical activity with change in temperature, and the specific rotation of the polymers changed from a positive to a negative value with decrease in temperature. The CD band of the polymers in the absorption region due to the main chain changed from a positive to a negative peak with a change in specific rotation. These results indicate that poly-2 and poly-5 undergo a thermally induced helix-helix transition in THF. The temperature for the helix-helix transition of poly-2 was independent of the degree of polymerization. Poly-2 exhibited a reversible helix-helix transition in chloroform and diethyl ether and also in THF, whereas in toluene and dichloromethane such a transition was not observed. Copyright
- Hino, Kyoko,Maeda, Katsuhiro,Okamoto, Yoshio
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p. 361 - 367
(2007/10/03)
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- Itraconazole and stereoisomers
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Anti-infective compositions for the treatment of a human in need of therapy for a systemic or topical fungal infection which comprise a pharmaceutically acceptable carrier and a therapeutically effective amount of (2R,4S) itraconazole or a pharmaceutically acceptable salt thereof, substantially free of its (2S,4R) stereoisomer.
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- Spiroconjugated charge-transfer dyes for optical applications
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New intramolecular charge-transfer organic dyes are described. The design of these molecules is based on the phenomenon of spiroconjugation, and it provides a modular approach to the preparation of unique materials with interesting optical properties. In the dyes of the invention, the lowest unoccupied molecular orbital (LUMO) of the acceptor part (based on indandione) is spiroconjugated with the highest unoccupied molecular orbital (HOMO) of the donor part (amines, alcohols and thiols). The interaction between the donor and acceptor is controlled by the energy and symmetry of the frontier orbitals. The novel dyes described herein, with predictable and tunable optical properties, can be used in many optical applications including nonlinear optics (NLO).
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- Tritiated chiral alkanes as substrates for soluble methane monooxygenase from Methylococcus capsulatus (Bath): Probes for the mechanism of hydroxylation
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The tritiated chiral alkanes (S)-[1-2H1, 1-3H]ethane, (R)-[1-2H1, 1-3H]ethane, (S)-[1-2H1, 1-3H]butane, (R)[1-2H1, 1-3H]but
- Valentine, Ann M.,Wilkinson, Barrie,Liu, Katherine E.,Komar-Panicucci, Sonja,Priestley, Nigel D.,Williams, Philip G.,Morimoto, Hiromi,Floss, Heinz G.,Lippard, Stephen J.
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p. 1818 - 1827
(2007/10/03)
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- Tri-substituted tetrahydrofuran antifungals
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An antifungal compound represented by formula [I]: wherein X is independently both F or both Cl or one X is F and the other is Cl; Y=R'= (C1-C10) alkyl; (C2-C10)alkenyl; (C2-C10)alkynyl; (C3-C8)cycloalky or CH2R2; R2= (C1-C3)perhaloalkyl; CO2R3 *CH(OR4)CH2OR4 or CH2N(R5) R3= lower alkyl or H R4= R3 or (CH2)2OR3 R5= lower alkyl Z=H, or (C1-C5) alkanoyl and the carbons with the asterisks (*) have the R or S absolute configuration; or a pharmaceutically acceptable salt thereof as well as pharmacetical compositions containing them and a methods of treating or preventing fungal infections in mammals using them are disclosed.
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- Alkylation of Several Nucleophiles with Alkylsulfonium Salts
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The reactions of dialkylphenylsulfonium salts (1) with several nucleophiles such as phenols, amine, enolate ion and thiolate ions, have been investigated.The relative reactivities of the alkyl groups of sulfonium salts for the phenolate ion (hard nucleophile) were as follows; Me:Et:i-Pr = 1.0:1.34:3.44.In the alkylation of the p-toluenethiolate ion (soft nucleophile) with 1, the opposite reactivity (Me:Et:i-Pr = 1.0:0.22:0.03) was found.When a sulfonium salt (1e) having an optically active (S)-s-butyl group was reacted with a phenolate ion, an optically active (R)-s-butyl phenyl ether was obtained with an inversion of the configuration at the chiral carbon atom.A reaction mechanism via a sulfurane intermediate is proposed for the alkylation of the phenolate ion with alkylsulfonium salts.The relative reactivities for the alkylation of several nucleophiles with dialkyl-phenylselenonium salts (12) were also investigated.
- Umemura, Kazuyuki,Matsuyama, Haruo,Kamigata, Nobumasa
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p. 2593 - 2600
(2007/10/02)
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- Alkylation with Oxalic Esters. Scope and Mechanism.
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Alkyl oxalates are well suited for use as standard synthetic reagents in N-, O-, or S-alkylations and often display an interesting regioselectivity.The mechanism seems to be a direct alkylation of the substrate anion.
- Bergman, Jan,Norrby, Per-Ola,Sand, Peter
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p. 6113 - 6124
(2007/10/02)
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- Reactions of 3-(Dimethylamino)-2,2-dimethyl-2H-azirines with Barbituric-Acid Derivatives
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The reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine (1) and 5,5-disubstituted barbituric acids 5 in i-PrOH at ca. 70 deg gives 2-alkanamides of type 6 in good yields (Scheme 1).The formation of 6 proceeds with loss of CO2; various reaction mechanisms with a zwitterionic 1:1 adduct B as common intermediate are discussed (Schemes 2 and 5).Thermolysis of product 6 leads to 2-alkyl-5-(dimethylamino)-4,4-dimethyl-4H-imidazoles 8 or the tautomeric 2-alkylidene derivatives 8'via elimination of HNCO (Scheme 3).The latter undergoes trimerization to give 1,3,5-triazine-2,4,6-trione.No reaction is observed with 1,5,5-trisubstituted barbiturates and 1 in refluxing i-PrOH, but an N-alkylation of the barbiturate occurs in the presence of morpholine (Scheme 4).This astonishing reaction is explained by a mechanism via formation of the 2-alkoxy-2-(dimethylamino)aziridinium ion H which undergoes ring opening to give the O-alkylated 2-amino-N1,N1-dimethylisobutyramide I as alkylating reagent (Scheme 4).
- Schlaepfer-Daehler, Marlise,Heimgartner, Heinz
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p. 2275 - 2286
(2007/10/02)
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