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21.
Prathama S. Mainkar Chirumarry Sridhar Ambadi Sudhakar Srivari Chandrasekhar 《Helvetica chimica acta》2013,96(1):99-108
The synthesis of bolaamphiphiles from unusual β‐amino acids or an alcohol and C12 or C20 spacers is described. Unusual β‐amino acids such as a sugar amino acid, an AZT‐derived amino acid, a norbornene amino acid, and an AZT‐derived amino alcohol were coupled with spacers under standard conditions to get the novel bolaamphiphiles 5 – 8 (Scheme 1), 12 and 13 (Scheme 2), and 17 and 20 (Scheme 3). Some of these compounds, on precipitation from MeOH/H2O, self‐assembled into organized molecular structures. 相似文献
22.
Biswanath Das Penagaluri Balasubramanyam Maddeboina Krishnaiah Boyapati Veeranjaneyulu Dega Sudhakar 《合成通讯》2013,43(14):2113-2121
Regio-, stereo-, and chemoselective ring opening of epoxides with thiols using Cu/MgO as a heterogeneous catalyst has efficiently been carried out to produce the corresponding β-hydroxy sulfides in excellent yields at room temperature under solvent-free conditions. The treatment of the epoxides with thiols and 50% aqueous H2O2 in the presence of the same catalyst at room temperature affords the β-hydroxy sulfoxides in excellent yields. 相似文献
23.
Facile and convenient one-pot cascade/tandem approaches for the syntheses of privileged medicinal scaffolds, 12-aryl-2,3,4,12-tetrahydrobenzo[b]xanthene-1,6,11-trione derivatives, have been reported under extremely mild reaction conditions using a catalytic amount of H2SO4 in water or in the presence of the acidic ionic liquid bmim[HSO4], which could be recycled. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
24.
Cerium(III) chloride heptahydrate (CeCl3·7H2O) catalyzes the reaction of substituted salicylaldehydes with 1,3-cyclohexane dione or dimedone in aqueous medium at reflux temperature to afford the corresponding 1-oxo-1,2,3,4,9,10-hexahydroxanthene derivatives4 0 in high yields. 相似文献
25.
Biswanath Das Yallamalla Srinivas Chittaluri Sudhakar Kongara Damodar Ravirala Narender 《合成通讯》2013,43(2):220-227
Bromination of alkenes and alkynes has efficiently been carried out at room temperature in short reaction times using KBr and diacetoxy iodobenzene in CH2Cl2-H2O (1:1) to prepare the corresponding trans-dibromo compounds in excellent yields. 相似文献
26.
Thermotropic main chain liquid crystalline polyurethanes were prepared from 4-{[4-(6-hydroxyhexyloxy)phenylimino]methyl}benzoic acid 4-{[4-(6-hydroxyhexyloxy)phenylimino]methyl}phenyl ester (mesogenic diol) and 1,6-hexamethylene di-isocyanate. The effects of partial replacement of the mesogenic diol by 20-50 mol% of poly(tetramethylene oxide)glycol (PTMG) of varying molecular mass (M n =650, 1000, 2000) on the liquid crystalline properties were studied. Structural characterization was carried out by FTIR spectroscopy and the molecular mass distribution was determined by GPC. Differential scanning calorimetry and hot stage polarizing optical microscopy were used to study the mesomorphic properties. It was observed that the partial replacement of the mesogenic diol by PTMG of varying molecular masses influenced the phase transitions and the occurrence of mesophase textures. When the molecular mass of PTMG was enhanced, a higher content of mesogenic agent was needed to obtain liquid crystalline properties. 相似文献
27.
An expedient procedure for the acylation of alcohols, phenols, and thiophenols using catalytic amount of Zn(OTf)2 is described. This procedure is highly suitable for industrial application due to use of less toxic metal as a part of catalyst, short reaction time at ambient temperature, without any racemization of chiral alcohols. 相似文献
28.
Sadiq‐ur‐Rehman Bilal Ahmad Khan Muhammad Aziz Chaudhary Khawaja Ansar Yasin Saqib Ali 《Heteroatom Chemistry》2015,26(6):417-425
Di‐ and triorganotin(IV) carboxylates, RnSn(OCOC(R2)=CHR1)4–n (n = 2 and 3; R = Me, Et, n‐Bu, Ph; R1 = 3‐CH3O‐4‐OHC6H3, R2 = C6H5) were prepared by reacting the corresponding organotin(IV) chloride with the silver salt of the (E)‐3‐(4‐hydroxy‐3‐methoxyphenyl)‐2‐phenylpropenoic acid. The title compounds were investigated and characterized by elemental analysis, infrared (FT‐IR), multinuclear (1H, 13C, 119Sn) NMR, and mass spectrometry, and possible structures were proposed. The complexes and ligand acid ( HL ) have been evaluated in vitro against various bacteria and fungi. The results noticed during the biocidal activity screenings proved their in vitro biological potential. They were also tested for cytotoxicity. 相似文献
29.
30.
Self‐Assembly of DNA–Oligo(p‐phenylene‐ethynylene) Hybrid Amphiphiles into Surface‐Engineered Vesicles with Enhanced Emission 下载免费PDF全文
Shine K. Albert Hari Veera Prasad Thelu Murali Golla Nithiyanandan Krishnan Soma Chaudhary Dr. Reji Varghese 《Angewandte Chemie (International ed. in English)》2014,53(32):8352-8357
Surface‐addressable nanostructures of linearly π‐conjugated molecules play a crucial role in the emerging field of nanoelectronics. Herein, by using DNA as the hydrophilic segment, we demonstrate a solid‐phase “click” chemistry approach for the synthesis of a series of DNA–chromophore hybrid amphiphiles and report their reversible self‐assembly into surface‐engineered vesicles with enhanced emission. DNA‐directed surface addressability of the vesicles was demonstrated through the integration of gold nanoparticles onto the surface of the vesicles by sequence‐specific DNA hybridization. This system could be converted to a supramolecular light‐harvesting antenna by integrating suitable FRET acceptors onto the surface of the nanostructures. The general nature of the synthesis, surface addressability, and biocompatibility of the resulting nanostructures offer great promises for nanoelectronics, energy, and biomedical applications. 相似文献