- Preparation of novel, functionalized 1,10-phenanthrolines
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The preparation of hydrophilic 2,9-dialkyl-1,10-phenanthrolines, including phenanthroline-5-sulfonic acids and phenanthrolines with side chain functionality is described. Nucleophilic aromatic substitution chemistry is used to obtain regiochemically defined phenanthroline sulfonic acids by much simpler means than have been available in the past.
- Mathis, Janette M.,Pallenberg, Alexander J.
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- l-Histidine-Derived Smart Antifouling Biohybrid with Multistimuli Responsivity
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A novel dual pH/thermoresponsive amphiphilic poly(histidine methacrylamide)-block-hydroxyl-terminated polybutadiene-block-poly(histidine methacrylamide) (PHisMAM-b-PB-b-PHisMAM) triblock copolymer biohybrid, composed of hydrophobic PB and ampholytic PHisMAM segments, is developed via direct switching from living anionic polymerization to recyclable nanoparticle catalyst-mediated reversible-deactivation radical polymerization (RDRP). The transformation involved in situ postpolymerization modification of living polybutadiene-based carbanionic species, end-capped with ethylene oxide, into dihydroxyl-terminated polybutadiene and a subsequent reaction with 2-bromo-2-methylpropionyl bromide resulting in a telechelic ATRP macroinitiator (Br-PB-Br). Br-PB-Br was used to mediate RDRP of an l-histidine-derived monomer, HisMAM, yielding a series of PHisMAM-b-PB-b-PHisMAM triblock copolymers. The copolymer’s stimuli response was assessed against pH and temperature changes. The copolymer is capable of switching among its zwitterionic, anionic, and cationic forms and exhibited unique antifouling properties in its zwitterionic form. These novel triblock copolymers are expected to be show promising potential in biomedical applications.
- Mohammad, Sk Arif,Dolui, Subrata,Kumar, Devendra,Mane, Shivshankar R.,Banerjee, Sanjib
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p. 3941 - 3949
(2021/08/23)
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- Total synthesis of (-)-goniomitine
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The total synthesis of (-)-goniomitine has been accomplished in 11 steps starting from commercially available diethyl l-malate. The synthesis features a chiral pool approach to prepare the chiral C-9 unit containing a quaternary carbon center, an Ir-catal
- Zhou, Shiqiang,Jia, Yanxing
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supporting information
p. 3416 - 3418
(2014/07/08)
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- Chlorination of aliphatic primary alcohols via triphosgene-triethylamine activation
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Activation of primary aliphatic alcohols with triphosgene and triethylamine mixtures afforded either alkyl chloride or diethylcarbamate products, and the switch in selectivity appeared to be driven by sterics. The reaction conditions to achieve this highly useful transformation were unexceptionally mild and readily tolerated by a wide range of sensitive functionalities.
- Ayala, Caitlan E.,Villalpando, Andres,Nguyen, Alex L.,McCandless, Gregory T.,Kartika, Rendy
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supporting information; experimental part
p. 3676 - 3679
(2012/09/08)
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- Process for the preparation of Drospirenone
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A process for the preparation of Drospirenone (I) according to the following scheme wherein the substituent R is defined in the description. The process improves the product yield and purity by reducing the formation of undesired side-products and is particularly convenient for industrial-scale manufacturing.
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Page/Page column 12-13
(2009/02/10)
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- Total synthesis of the calphostins: Application of Fischer carbene complexes and thermodynamic control of atropisomers
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The total syntheses of the potent protein kinase C inhibitors calphostins A, B, C, and D as well as a variety of structural analogues are reported. An aminobenzannulation reaction of an enantiopure chromium Fischer carbene complex is utilized to prepare a pentasubstituted naphthylamine. After optimization of side-chain substituents, conversion of the naphthylamine to an o-naphthoquinone was followed by biomimetic oxidative dimerization using trifluoroacetic acid and air yielding a 1:2 P/M mixture of atropisomeric perylenequinones. Thermal equilibration to a 3:1 P:M atropisomeric ratio and separation of the perylenequinones followed by side chain desymmetrization and functionalization led to the total synthesis of enantio- and diastereomerically pure calphostin C in only twelve steps from commercially available starting materials. In addition, calphostins A, B, D, and several structural analogues were prepared to evaluate biological activities.
- Merlic,Aldrich,Albaneze-Walker,Saghatelian,Mammen
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p. 1297 - 1309
(2007/10/03)
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- Synthesis of conformationally constrained 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine inhibitors of Farnesyltransferase
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(Equation Presented) Synthesis of the 8-amino-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine ring system was accomplished by intramolecular cyclization of an iminium ion, derived from condensation of an amine and a substituted γ-(1-imidazolyl)butyraldehyde. The
- Dinsmore, Christopher J.,Zartman, C. Blair,Baginsky, Walter F.,O'Neill, Timothy J.,Koblan, Kenneth S.,Chen, I-Wu,McLoughlin, Debra A.,Olah, Timothy V.,Huff, Joel R.
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p. 3473 - 3476
(2007/10/03)
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- 29Si NMR spectra of tert-butyldimethylsilylated alcohols
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29Si NMR spectra of a series of tert-butyldimethylsilyl derivatives of simple alcohols were measured under standard conditions in chloroform-d. The chemical shifts are linearly related to those in analogous trimethylsilyl derivatives. The corre
- Schraml, Jan,Kvi?c?alova?, Magdalena,Blechta, Vratislav,C?erma?k, Jan
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p. 659 - 662
(2007/10/03)
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- Total Synthesis of Ionophore Antibiotic X-14547A
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A highly stereocontrolled and convergent total synthesis of optically active ionophore antibiotic X-14547A (1) was designed and carried out.Degradative reactions led to the key intermediates 3 and 6, which served as convenient comparison stages.The tetrah
- Nicolaou, K. C.,Papahatjis, D. P.,Claremon, D. A.,Magolda, R. L.,Dolle, R. E.
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p. 1440 - 1456
(2007/10/02)
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