• Carbon letters
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• 제13권1호
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• pp.29-33
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• 2012

A novel strategy for the simultaneous reduction and functionalization of graphene oxide (G-O) was developed using polyallylamine hydrochloride (PAAH) as a multi-functional agent. The G-O functionalization by PAAH was carried out under basic conditions to catalyze the epoxide ring opening reaction of G-O with abundant amine groups of PAAH. We found that G-O was not only functionalized with PAAH but also reduced under the reaction condition. Moreover, the synthesized PAAH-functionalized G-O sheets were soluble in water and applicable to the synthesis of nanocomposites with gold nanoparticles.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.389-396
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• 2009

MFI structural zeolite (ZSM-5 or Sililcalite) was treated with HF solution to introduce mesoporous channels in the microporous crystals. Inner mesopore size could be controlled from 2.5 to 3.5 nm by changing the concentration of HF solution. The pore structure of HF-treated MFI zeolite was studied by instrumental analysis. The active Co (III) salen complex monomers were successfully anchored non-covalently on the surfaces of mesoporous MFI-type zeolite. These heterogeneous catalysts could be applied in asymmetric ring opening of terminal epoxides by phenol derivatives. It showed very high enantioselectivity and yield up to 95% in the catalytic synthesis of optically active $\alpha$-aryloxy alcohol compounds.

• 한국군사과학기술학회지
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• 제8권1호
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• pp.69-80
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• 2005

A synthesis of azide-terminated glycidyl azide polymer, GAP-A, was carried out by tosylation and azidation of polyepichlorohydrin(PECH) prepared by cationic ring-opening polymerization. Polyepichlorohydrin was prepared by cationic activated monomer polymerization using ethylene glycol and $BF_3{\cdot}OEt_2$ as an initiator and a catalyst at $\~10^{\circ}C$. Tosylation of polyepichlorohydrin was performed using traditional TsCl/pyridine method and was also carried out using TsCl/amine catalysts to reduce the reaction time significantly. Azidation of tosyl-terminated PECH(OTs-PECH) was performed using $NaN_3$ as an azidation reagent in DMF solvent at high temperature and was unexpectedly completed within 2 hours.

• 한국군사과학기술학회지
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• 제7권2호
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• pp.109-117
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• 2004

We synthesized energetic prepolymer(2-nitrato ethyl oxirane, NEO) for plastic-bonded explosive and measured its thermodynamic parameters. 2-Nitrato ethyl oxirane(NEO) as a monomer was synthesized from 4-butene-ol, the first-step was preparation of 1-nitrate-3-butene and second-step was synthesized 2-nitrate-ethyl oxirane from 1nitrate-3-butene and then polymerized by cationic ring opening polymerization. The unreacted monomer concentration was measured by GC. The thermodynamic parameters were obtained from the ceiling temperature(Tc) values of 1 mole monomer at each reaction temperature. We varied feed rate of monomer, concentration of initiator and monomer to control molecular weight and polydispersity of perpolymer(NEO). Number average molecular weight(Mn), polydispersity(PD), and glass transition temperature(Tg), viscosity of prepolymer(NEO) were 2000, 1.07, $-55^{\circ}C$ and 300 poise respectively.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.959-965
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• 2005

Investigation of structure-activity relationships of novel quinazolines has identified 7,8-dihydro-[1,4]dioxino-[2,3-g]quinazolines as a potent inhibitor of EGFR. These compounds have a benzodioxane framwork, which was prepared by regioselective O-alkylation of ethyl 3,4-dihydroxy benzoate by epoxide ring opening. Compounds 3f and 3k were more potent than ZD-1839 in EGF enzyme and EGFR autophosporylation inhibition assays.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.840-844
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• 2010

The new MPV type reagent, Al-methanesulfonyldiisobutylalane ($DIBAO_3SCH_3$), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined in order to find out a new reducing system with high selectivity in organic synthesis. In general, the reagent is extremely mild, showing only reactivity toward aldehydes, ketones and epoxides. The reagent exhibits a unique reducing applicability in organic synthesis. Thus, the reagent can achieve a clean 1,2-reduction of $\alpha,\beta$-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in 100% purity. In addition, the reagent shows an excellent regioselectivity in the ring-opening reaction of epoxides. Finally, $DIBAO_3SCH_3$ shows a high stereoselectivity in the reduction of cyclic ketones to produce the thermodynamically more stable epimers exclusively.

• 약학회지
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• 제56권4호
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• pp.230-235
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• 2012

Synthesis of novel cyclopropyl pyrimidine and purine nucleoside derivatives 2~8 with ${\alpha}$-configuration was successfully accomplished using an epoxide-ring opening reaction, lactonization, a hydroboration-oxidation reaction and a Mitsunobu reaction as the key steps. Antiviral activities against HSV-1 and -2, HIV-1 and -2, coxsackie B1and B3 viruses and poliovirus were assayed. Three compounds 4, 7 and 8 exhibit cytotoxicity-derived antiviral activity only in HIV-1 and -2.

• 대한화학회지
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• 제60권4호
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• pp.257-260
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• 2016

A new perfluorobutyl substituted cyclic type disodium alkanesulfonate is designed, synthesized and characterized as alternative substance to perfluorooctane sulfonic acid (PFOS, 1), a well-known surfactant. Cylic type sulfonate was accomplished from commercially available 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol in four steps. Bio-degradable perfluorobutyl moiety was introduced from fluorous diol, which is symmetrically substituted amphiphile via installation of an intermediate trifluoromethanesulfonyl ester and easily manipulated by double displacement of triflate using potassium malonate and further reduction followed by nucleophilic ring opening are key reactions to get target disodium alkanesulfonate. The efficiency and simplicity in the synthesis of this material offer a new strategy to design PFOS alternatives.

• Journal of Radiation Protection and Research
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• 제30권1호
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• pp.31-34
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• 2005

The article is devoted to the study of some hi-and tricyclic derivatives of aziridine as materials lot newindicators of ionizing radiation. To create high sensitive materials some aspects of photo induced ring opening processes in aziridine derivatives in ethanol solutions and in polymeric matrix were studied and two steps character of the processes investigated was established. Two types of radioindicators were suggested and preliminary tested. The new way of synthesis of radiochromic derivatives of aziridine was developed and series of target compounds synthesized.

• Macromolecular Research
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• 제10권6호
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• pp.359-364
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• 2002

A series of PLA-PEO-PLA triblock stereo-copolymers with varying PLA/PEO and L-DL-LA ratios were synthesized via ring opening pelymerizations. Aqueous solutions of these copolymers undergo thermo-responsive phase transitions as the temperature monotonically increases. Further study shows that there is a critical gel concentration (CGC), and also lower and upper critical gel temperatures (CGTs), at which the thermo-responsive phase transition occurs. The CGC and CGTs are affected by various factors such as block length, as well as the compositions of the PLA blocks and of the additives. In particular, the changes in the phase diagram produced by varying the L-/DL-LA ratio in the PLA blocks were determined to be mainly due to consequent stereo-regularity changes in the PLA blocks.