• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.117-120
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• 2013

The reactions of indole with carbonyl groups have been efficiently carried out in the presence of catalytic amounts of 1,3-dibromo-5,5-dimethylhydantoin under solvent-free conditions and corresponding bis(indolyl)-mathanes were obtained in good to excellent yields. Synthesis of di[bis(indolyl)methyl]benzene was also accomplished by this catalyst. Furthermore, chemoselective conversion of aromatic aldehydes to their corresponding bis(indolyl)methanes in the presence of aliphatic aldehydes or ketones was achieved by this method.

• Macromolecular Research
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• v.12 no.1
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• pp.94-99
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• 2004

We have performed Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) studies on blends of poly(vinyl phenol) (PVPh) with poly(n-alkylene 2,6-naphthalates) containing alkylene units of different lengths. The results indicate that each poly(ethylene 2,6-naphthalate) (PEN) and poly(trimethylene 2,6-naphthalate) (PTN) blend with PVPh is immiscible or partially miscible, but blends of poly(butylene 2,6-naphthalate) (PBN) with PVPh are miscible over the whole range of compositions in the amorphous state. FTIR spectroscopic analysis confirmed that significant degree of intermolecular hydrogen bonding occurs between the PBN ester carbonyl groups and the PVPh hydroxyl groups. The large difference in the degree of mixing in these blend systems is described in terms of the effect that chain mobility has on the accessibility of the ester carbonyl functional groups toward the hydroxyl groups of PVPh, which in turn impacts the miscibility of these blends.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.33-39
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• 1993

Polymerized vesicles were prepared from monomeric cholesterol-containing surfactant. These vesicles were used to extract the free cholesterol. To introduce spacer group into [cholesteryloxycarbonylmethyl] [2-(methacryloyloxy)ethyl]dimethylammonium chloride (CHODAMA), [5-[ (cholesteryloxy)carbonyl]pentyl] [2-(methacryloyloxy)ethyl]dimethylammonium bromide (CHODAMA-5) and [10-[(cholesteryloxy)carbonyl]decyl] [2-(methacryloyloxy)ethyl]dimethylammonium bromide (CHODAMA-10) were synthesized, In both case of polymerized vesicle with CHODAMA-5 and CHODAMA-10, the permeability was decreased and the amount of extracted cholesterol was also decreased, compared with the polymerized vesicle of CHODAMA.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.102-103
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• 1989

Four coordinated rhodium(Ⅰ) complexes, Rh($ClO_4$)(CO)$(PPh_3)_2$ and [$Rh(CO)(PPh_3)_3$]$ClO_4$(2) catalyze the iosmerization of allylic alcohols to the corresponding carbonyl compounds at room temperature under nitrogen. The isomerization is faster with 2 than with 1, which is understood in terms of relative ease of the last step of the catalytic cycle, the reductive elimination of enol. Relative rates of the isomerization with 1 and 2 for different allylic alcohols are also explained by the relative ease of the enol elimination step in part. The first step of the catalytic cycle, the complex formation of the allylic alcohol through the ${\pi}-system$ of the olefinic group of the allylic alcohol and the following step, formation of hydridoallyl complex also seem to affect the overall rate of the isomerization.

• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.128-131
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• 1996

From Raman spectra, the ${\nu}g$C=O frequencies of 4-substituted benzaldehydes were found to correlate with the ${\sigma}_p$ values of the 4-x atom or group as well as the acceptor number (AN) values of solvents. In various solvents, the ${\nu}g$C=O frequency of benzaldehyde decreased upon the increase of benzaldehyde concentration. This shift was mainly due to the hydrogen bonding between the carbonyl oxygen and/or aldehydic proton of benzaldehyde and the solvent molecules. Over the 1-80 volume % change, the ${\nu}g$C=O frequency of benzaldehyde down shifted from 1709.4 $cm^{-1}$ to 1700.2 $cm^{-1}$ in CCl4 solution and from 1703.0 $cm^{-1}$ to 1698.0 $cm^{-1}$ in $C_2H_5OH$ solution. This is due to the fact that hydrogen bonding between the benzaldehyde and C2H5OH was much stronger than that between the benzaldehyde and the other solvents.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.900-905
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• 1996

Details are described of reaction of carbonyl compounds with diisobutyldialkylaminoalane (DIBAL-NR2; R=Et, i-Bu, Ph) in order to establish their reduction characteristics. The reagents were extremely mild and reduced only aldehydes and ketones effectively in ethyl ether at 25 ℃. The stereoselectivity in the reduction of representative cyclic ketones appeared not so high but quite different from that obtained by DIBAL-H itself. The reagents reduced α,β-unsaturated aldehydes and ketones to the corresponding allylic alcohols without any detectable 1,4-reduction products. DIBAL-NR2 also achieved the selective reduction of aldehydes or ketones in the presence of keto or other readily reducible functional group, however the chemoselectivity was less satisfactory than that achieved by diisobutylethoxyalane (DI-BAL-OEt).

• Journal of Photoscience
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• v.9 no.2
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• pp.356-358
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• 2002

Regioselective 3$^1$-$^{18}$ O-labelling of chlorophyll derivatives possessing a 3-formyl group such as methyl (pyro) pheophorbide-d (3, 4) was carried out efficiently by a simple one-step procedure; by stirring a homogeneous solution of tetrahydrofuran and H$_2$$^{18}$ O containing a small amount of trifuluoroacetic acid.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1767-1770
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• 2005

Novel 1',4'-dimethyl branched carbocyclic nucleosides were synthesized from acetol. The 4'-methyl group was installed via a Claisen rearrangement reaction, and the carbonyl addition of methylmagnesium bromide was used to introduce the 1'-methyl group. The coupling of nucleosidic bases and desilylation was used to produce a series of novel nucleosides.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.976-980
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• 2006

The synthesis of 4'-phenyl and 1'-methyl doubly branched carbocyclic nucleoside was accomplished from 2-hydroxy acetophenone. The 4'-phenyl group was installed via a [3,3]-sigmatropic rearrangement reaction, and the carbonyl addition of methylmagnesium bromide was used to introduce the 1'-methyl group. Cyclization of divinyl 9 was performed using $2^{nd}$ generation Grubbs catalyst. The coupling of cyclopentenol 12$\alpha$ with 6-chloropurine by Mitsunobu reaction and desilylation was used to synthesize the target nucleoside 15.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1156-1158
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• 2007

Valerophenone shows a dramatic shift of photoreactivity by a cyclopropyl group at alpha position to the carbonyl group. By the minor change of structure, the diastereoselectivity of the Yang photocyclization is reversed and the ratio of cyclization to elimination products increases significantly.