- Diverse Proton-Conducting Nanotubes via a Tandem Macrocyclization and Assembly Strategy
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Macrocycles that assemble into nanotubes exhibit emergent properties stemming from their low dimensionality, structural regularity, and distinct interior environments. We report a versatile strategy to synthesize diverse nanotube structures in a single, efficient reaction by using a conserved building block bearing a pyridine ring. Imine condensation of a 2,4,6-triphenylpyridine-based diamine with various aromatic dialdehydes yields chemically distinct pentagonal [5 + 5], hexagonal [3 + 3], and diamond-shaped [2 + 2] macrocycles depending on the substitution pattern of the aromatic dialdehyde monomer. Atomic force microscopy and in solvo X-ray diffraction demonstrate that protonation of the macrocycles under the mild conditions used for their synthesis drives assembly into high-aspect ratio nanotubes. Each of the pyridine-containing nanotube assemblies exhibited measurable proton conductivity by electrochemical impedance spectroscopy, with values as high as 10-3 S m-1 (90% R.H., 25 °C) that we attribute to differences in their internal pore sizes. This synthetic strategy represents a general method to access robust nanotube assemblies from a universal pyridine-containing monomer, which will enable systematic investigations of their emergent properties.
- Strauss, Michael J.,Jia, Manping,Evans, Austin M.,Castano, Ioannina,Li, Rebecca L.,Aguilar-Enriquez, Xavier,Roesner, Emily K.,Swartz, Jeremy L.,Chavez, Anton D.,Enciso, Alan E.,Stoddart, J. Fraser,Rolandi, Marco,Dichtel, William R.
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supporting information
p. 8145 - 8153
(2021/06/21)
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- Cooperative Self-Assembly of Pyridine-2,6-Diimine-Linked Macrocycles into Mechanically Robust Nanotubes
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Nanotubes assembled from macrocyclic precursors offer a unique combination of low dimensionality, structural rigidity, and distinct interior and exterior microenvironments. Usually the weak stacking energies of macrocycles limit the length and mechanical
- Strauss, Michael J.,Asheghali, Darya,Evans, Austin M.,Li, Rebecca L.,Chavez, Anton D.,Sun, Chao,Becker, Matthew L.,Dichtel, William R.
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supporting information
p. 14708 - 14714
(2019/11/05)
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- Equilibration of Imine-Linked Polymers to Hexagonal Macrocycles Driven by Self-Assembly
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Macrocycles based on directional bonding and dynamic covalent bond exchange can be designed with specific pore shapes, sizes, and functionality. These systems retain many of the design criteria and desirable aspects of two-dimensional (2D) covalent organi
- Chavez, Anton D.,Evans, Austin M.,Flanders, Nathan C.,Bisbey, Ryan P.,Vitaku, Edon,Chen, Lin X.,Dichtel, William R.
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supporting information
p. 3989 - 3993
(2018/03/01)
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- FeCl3-catalyzed self-cleaving deprotection of methoxyphenylmethyl-protected alcohols
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4-Methoxyphenylmethyl ethers are widely utilized as alcohol protecting groups. FeCl3 effectively catalyzes the deprotection of methoxyphenylmethyl-type ethers in a self-cleaving manner to produce oligomeric derivatives and alcohols. Remarkably, the highly pure mother alcohols can be obtained without silica gel column chromatography by using the 2,4-dimethoxyphenylmethyl group as a protective group.
- Sawama, Yoshinari,Masuda, Masahiro,Asai, Shota,Goto, Ryota,Nagata, Saori,Nishimura, Shumma,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 434 - 437
(2015/03/03)
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- Synthesis of structural analogues of hexadecylphosphocholine and their antineoplastic, antimicrobial and amoebicidal activity
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Twelve derivatives of hexadecylphosphocholine (miltefosine) were synthesized to determine how the position and length of the alkyl chain within the molecule influence their biological activities. The prepared alkylphosphocholines have the same molecular formula as miltefosine. Activity of the compounds was studied against a spectrum of tumour cells, two species of protozoans, bacteria and yeast. Antitumour efficacy of some alkylphosphocholines measured up on MCF-7, A2780, HUT-78 and THP-1 cell lines was higher than that of miltefosine. The compounds showed antiprotozoal activity against Acanthamoeba lugdunensis and Acanthamoeba quina. Some of them also possess fungicidal activity against Candida albicans equal to miltefosine. No antibacterial activity was observed against Staphylococcus aureus and Escherichia coli. A difference in position of a long hydrocarbon chain within the structure with maximum efficacy was observed for antitumour, antiprotozoal and antifungal activity.
- Timko, Luká?,Fischer-Fodor, Eva,Garajová, Mária,Mrva, Martin,Chereches, Gabriela,Ondriska, Franti?ek,Bukovsky, Marián,Luká?, Milo?,Karlovská, Janka,Kubincová, Janka,Devínsky, Ferdinand
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p. 263 - 273
(2015/05/26)
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- Rapid configuration analysis of the solenopsins
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A protocol for rapid access to the relative and absolute configurations of the solenopsins, the venom alkaloids of fire ants (Solenopsis spp.), was developed based on chiral capillary gas chromatography. The synthesis of racemic mixtures of 2-methyl-6-alkylpiperidines and the isolation of natural (2R,6R)- and (2R,6S)-2-methyl-6-undecylpiperidines allowed for the standardization of the chromatographic method. Application of this protocol revealed the previously unknown natural occurrence of four stereoisomers of 2-methyl-6-undecylpiperidine in venom samples from workers and gynes of Solenopsis saevissima.
- Pianaro, Adriana,Fox, Eduardo G.P.,Bueno, Odair C.,Marsaioli, Anita J.
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experimental part
p. 635 - 642
(2012/09/22)
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- Synthetic organic electrochemistry in ionic liquids: The viscosity question
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Ionic liquids are obvious candidates for use in electrochemical applications due to their ionic character. Nevertheless, relatively little has been done to explore their application in electrosynthesis. We have studied the Shono oxidation of arylamines and carbamates using ionic liquids as recyclable solvents and have noted that the viscosity of the medium is a major problem, although with the addition of sufficient co-solvent, good results and excellent recovery and recycling of the ionic liquid can be achieved.
- Bornemann, Steven,Handy, Scott T.
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experimental part
p. 5963 - 5974
(2011/09/13)
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- Copper-catalyzed cross-coupling reaction of organoboron compounds with primary alkyl halides and pseudohalides
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Non-activated alkyl electrophiles, including alkyl iodides, bromides, tosylates, mesylates, and even chlorides, underwent copper-catalyzed cross-coupling with aryl boron compounds and alkyl 9-BBN reagents (see scheme; 9-BBN=9-borabicyclo[3.3.1]nonane). The reactions proceed with practically useful reactivities and thus complement palladium- and nickel-catalyzed Suzuki-Miyaura coupling reactions of alkyl halides.
- Yang, Chu-Ting,Zhang, Zhen-Qi,Liu, Yu-Chen,Liu, Lei
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supporting information; experimental part
p. 3904 - 3907
(2011/05/15)
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- Amphiphilic organocatalyst for schotten-baumann-type tosylation of alcohols under organic solvent free condition
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A Tosylation of primary alcohol with tosyl chloride was performed effectively with an W-hexadecylimidazole catalyst in water containing K 2CO3 aggregation of the catalyst carrying a hydrophobic methylene chain worked as a substitute for organic solvent.
- Asano, Keisuke,Matsubara, Seijiro
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supporting information; experimental part
p. 1757 - 1759
(2009/09/06)
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- Mild and efficient indium metal catalyzed synthesis of sulfonamides and sulfonic esters
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A facile and efficient method for synthesizing sulfonamides was developed using a catalytic amount of indium metal. A wide range of sulfonamides were synthesized in excellent yields using the new process. The method showed a generality for substrates including less nucleophilic and sterically hindered anilines, and it is also applicable for preparing sulfonic esters from sulfonyl chlorides and alcohols. Georg Thieme Verlag Stuttgart.
- Kim, Joong-Gon,Doo, Ok Jang
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p. 2501 - 2504
(2008/02/13)
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- Solvent-free and selective tosylation of alcohols and phenols with p-toluenesulfonyl chloride by heteropolyacids as highly efficient catalysts
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Tosylation of some alcohols and phenols has been directly carried out with p-toluenesulfonyl chloride using heterodoxy acids (H3PW 12O40, H3PMo12O40, A 3PW12O40, and AlPMo12O40) as catalysts in the absence of solvent. We found that heteropoly acids AlPW12O40 and AlPMo 12O40 were effective catalysts for the tosylation of alcohols and phenols. In the case of aliphatic alcohols, secondary alcohols undergo tosylation chemoselectively in the presence of primary hydroxyl groups. This new method consistently has the advantage of excellent yields and short reaction time.
- Fazaeli, Razieh,Tangestaninejad, Shahram,Aliyan, Hamid
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p. 812 - 818
(2007/10/03)
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- Synthesis of polyfluorinated ethers
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Procedures for preparing polyfluorinated ethers H(CF2CF 2)nCH2OR by alkylation of the corresponding telomeric alcohols H(CF2CF2)nCH2OH (n = 1-3) with alkyl halides and alkyl tosylates were examined.
- Bazhin,Gorbunova,Zapevalov,Saloutin
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p. 1646 - 1650
(2007/10/03)
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- ZrCl4 as an efficient catalyst for selective tosylation of alcohols with p-toluenesulfonic acid
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Tosylation of alcohols has directly been carried out with p-toluenesulfonic acid in methylene chloride under reflux using ZrCl4 as a catalyst. Primary alcohols were found to be tosylated chemoselectively over secondary alcohols.
- Das, Biswanath,Reddy, Vtukuri Saidi
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p. 1428 - 1429
(2007/10/03)
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- An efficient and selective tosylation of alcohols with p-toluenesulfonic acid
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Silica chloride has been found to be an efficient catalyst for facile tosylation of alcohols directly with p-toluenesulfonic acid in methylene chloride under reflux. The process is associated with selective tosylation of secondary alcohols over primary al
- Das, Biswanath,Reddy, V. Saidi,Reddy, M. Ravinder
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p. 6717 - 6719
(2007/10/03)
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- Cobalt(II) catalyzed tosylation of alcohols with p-toluenesulfonic acid
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Cobalt(II) chloride hexahydrate (CoCl2·6H2O) has been found to catalyze the tosylation of both aliphatic and aromatic alcohols with p-toluenesulfonic acid (p-TsOH) in high yields in 1,2-dichloroethane under reflux (ca. 80°C). In the
- Velusamy, Subbarayan,Kumar, J. S. Kiran,Punniyamurthy
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p. 203 - 205
(2007/10/03)
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- An efficient one pot synthesis of carbamate esters through alcoholic tosylates
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An efficient O-alkylation of alcoholic tosylates with amines in a K2CO3/CO2 system in the presence of tetrabutyl ammonium iodide (TBAI) provides exclusive formation of carbamates.
- Chaturvedi, Devdutt,Kumar, Atul,Ray
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p. 2651 - 2655
(2007/10/03)
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- Toluenesulfonate-acyl esters of ethylene glycol and other 1,2-diols as industrial antioxidants with cupric ion
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Ethylene glycol esters of soybean oil FA increased in viscosity much more slowly than methyl or glycerol esters when oxidized at 105°C in the presence of flowing air and colloidal copper. This increased stability was caused by a minor constituent of the e
- Jiang, Yongyi Julia,Hammond, Earl G.
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p. 791 - 796
(2007/10/03)
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- Process for preparation of oxyglutaric acid ester derivatives
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A process for preparing an oxyglutaric acid ester derivative of the formula: STR1 in which each of R1 and R2 is C1-5 alkoxy, C1-7 aralkyloxy, C7-9 halogenated aralkyloxy or phenyl, R4 is a hydroxyl-protecting group, and R5 is C1-10 alkyl which may have a substituent, comprises the steps of reacting a methyl phosphonate derivative or methyl phosphine oxide derivative with an oxyglutaric acid mono-ester to give a reaction product which comprises an oxyglutaric acid derivative having a phosphorus-containing group and a pentenedioic acid mono-ester (by-product), removing the pendenedioic acid mono-ester from the reaction product to isolate the oxyglutaric acid derivative, and converting the isolated oxyglutaric acid derivative into the oxyglutaric acid ester derivative. A process for obtaining an optically active oxyglutaric acid ester derivative is also disclosed.
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- Synthesis of Long Alkyl Chain Mono- and Di-N-substituted 4-Amino-N-methylphthalimides. Comparison of N-Alkylation Methods
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4-Amino-N-methylphthalimide, 1, was N-alkylated with the respective n-alkyl sulfonates and halides.In the former case, the di-derivative 4 was favored, while in the latter case, under phase transfer catalysis, the mono-derivative 3 was predominant.
- Amarilio, David S.,Varveri, Fannie S.
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p. 139 - 144
(2007/10/02)
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- REACTION OF PHOSPHORUS OXYACID ESTERS WITH p-TOLUENESULFONIC ACID
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The reaction of primary alkyl esters of phosphorus oxyacids with p-toluenesulfonic acid (TsOH) in refluxing solvents gave the corresponding p-toluenesulfonates (TsOR).We found that the secondary alkyl esters reacted with TsOH at lower temperature (r.t.-40 deg C) to afford TsORs in good yields.It is suggested that sulfonic acids may be useful for the selective dealkylation of mixed esters.Keywords-p-toluenesulfonic acid; p-toluenesulfonate; trialkyl phosphate; trialkyl phosphite; dialkyl phenylphosphonate; transesterification; dealkylation; solvolysis.
- Nitta, Yoshihiro,Arakawa, Yasushi,Ueyama, Naoto
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p. 2710 - 2718
(2007/10/02)
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