• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1351-1354
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• 2004

Tetracyclic 5-azaindole analogues were prepared by palladium-catalyzed sequential annulation of benzylidene(3-iodopyridinyl-4-yl)amine and 1-aryl substituted internal alkynes under $Pd(OAc)_2,\;n-Bu_4NCl,\;and Et_3N\;at\;120^{\circ}C.$ The synthetic procedure showed possible diversification of tetracyclic 5-azaindole analogues by varying the 1-aryl substituent in internal alkynes.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.92-97
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• 2011

The effect of Group I alkali acetate promoters on vinyl acetate (VA) synthesis was evaluated. Catalyst product selectivity and ethylene conversion are compared to the unpromoted catalyst in the fixed-bed reactor with oxidation reaction of ethylene and acetic acid in gaseous phase over Pd-Au/$SiO_2$ catalyst. It was found that: a) the promoters were stabilized on the catalyst surface, b) common effect for the alkali promoted Pd-Au catalysts increaseed in product selectivity and ethylene conversion compared to unpromoted catalyst (these effects increase from top to the bottom of Group I). These promoting effect is due to the common-ion effect of acetate, present in the reaction, resulting in an increase in the activity of the catalyst. In addition a complementary theory for the effect of Au in the structure of the catalyst is proposed the imposition of distribution of palladium particles through decreasing the particle's diameter.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1079-1085
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• 1999

An investigation was made of the effect of various transition metal catalysts, ligands, and a promoter on the synthesis of N,N'-diphenylurea(DPU) from nitrobenzene, aniline, and carbon monoxide. Homogeneous Pd and Ni catalysts were found to be highly efficient, giving almost quantitative isolated DPU yields at 100% nitrobenzene conversion. Bidentate ligand, 1,3-bis(diphenylphosphino)proane(dppp) showed much improved activity and significantly different reactivity relative to the usual monodentate $PPh_3$ ligand in the presence of Ni and Pd catalysts. These results were inferred to the effect of the cis coordination of bidentate dppp ligand on the metal. The use of a promoter $Et_4NCl$ was indispensable in the case of $PPh_3$, yet inhibited the reaction if used with dppp. It was possible to reuse the Pd-dppp catalyst system, although the catalytic activity was reduced slowly.

• Journal of the Korean Chemical Society
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• v.44 no.1
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• pp.30-36
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• 2000

Upon Pd(0)-catalyzed coupling reaction of (2R)-2-(N,N-ditosylimido)-3-butenyl methyl malonate (4) which was selected for the total synthesis of A-factor, (3R)-2-(6-methylheptanoyl)-3-hydroxy methyl-4-buttinolide (1), an unexpected 14-membered cyclic compound, bis(2-methoxycabonyl-(4E)-hexenolide) (15) was obtained. The structure of this compound was conformed by X-ray crystallography. This result implies that this method can be applied the synthesis of various size of symmetrical macrocyclic compounds.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.183-188
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• 2001

Ionic conjugated polymer, poly(2-ethynyl-N-propargylpyridinium bromide), was prepared by the cyclopolymerization of 2-ethynyl-N-propargylpyridinium bromide on using various transition metal catalysts, or by thermal methods without adding catalyst. The polymerization of 2-ethynyl-N-propargylpyridinium bromide catalyzed by PdCl2 gave the resulting polymers in relatively high yields. The polymer structure was characterized by various instrumental methods to confirm the conjugated polymer backbone structure carrying cumulated pyridine moiety. The polymers prepared by PdCl2 in DMSO or m-cresol were completely soluble in DMF, DMSO, and formic acid. The inherent viscosities of the resulting polymers were in the range of 0.07-0.19 dL/g. Thermal properties of the polymers were also discussed.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1387-1390
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• 2011

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3382-3384
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• 2010

A new synthetic route to ($\pm$)-aspidospermidine was devised, starting from the cycloadduct of 3-ethyl-5-bromo-2-pyrone with vinyl sulfide through a tandem conjugate addition-alkylation sequence. The requisite 3-ethyl-5-bromo-2-pyrone was prepared via the C3-selective Pd-catalyzed coupling reaction with $Et_3Al$-dimethylaminoethanol complex.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1761-1764
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• 2010

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.915-916
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• 2007

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.27-28
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• 2004