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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Bulletin of the Korean Chemical Society
Journal Basic Information
Journal DOI :
Korean Chemical Society
Editor in Chief :
Byeong Moon Kim
Volume & Issues
Volume 8, Issue 6 - Dec 1987
Volume 8, Issue 5 - Oct 1987
Volume 8, Issue 4 - Aug 1987
Volume 8, Issue 3 - Jun 1987
Volume 8, Issue 2 - Apr 1987
Volume 8, Issue 1 - Feb 1987
Selecting the target year
Polarographic Behavior of Oxovanadium (IV) Complex of Mercaptopyridine N-Oxide
Shim, Yoon-Bo ; Choi, Sung-Nak ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 225~230
The redox properties of 2-mercaptopyridine N-oxide (mpno) and its oxovanadium complex,
have been studied by the use of polarography and cyclic voltammetry. The radical anion of mpno is generated in acetone and is adsorbed to the electrode to form an adsorption wave at -0.21 V vs Ag/AgCl electrode. The normal wave appeared at -0.50 V is attributed to the formation of radical anion. The
exhibits one oxidation wave at +0.57 V, and two reduction waves at -1.07 V and -1.76 V vs. Ag/AgCl electrode; the oxidation is fully reversible one-electron process (
The reduction wave at -1.07 V is quasireversible and is arised from the formation of
The second reduction wave at -1.76 V is irreversible and this reduction process consists of two one-electron steps. The sulfur containing ligands seem to enhance the stability of lower oxidation state of vanadium while the oxygen or nitrogen donor of the ligands stabilize the higher oxidation state of vanadium when comparisons are made among several oxovanadium complexes.
Proton Magnetic Resonance Study of the Amino Group of Thioacetamide (TA) I. Quadrupole Relaxation Effects in NH
Suhr, Jae-Ryun ; Yoon, Chang-Ju ; Ro, Seong-Gu ; Choi, Young-Sang ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 230~232
Nitrogen-14 quadrupolar relaxation has been observed in the amino proton nmr spectra of TA in acetone and methanol solutions over the temperature range
The proton nmr lineshapes were analyzed to yield a
spin lattice relaxation time
as a function of temperature. Activation energies and correlation times at
for the molecular reorientation in the two solution phases have been calculated and the results are discussed.
Kinetics of the 1,3-dipolar Cycloaddition of p-substituted 3-phenylsydnones with DMAD
Youn, Byoung-Hee ; Lyu, Hak-Soo ; Han, Jee-Hyun ; Hahn, Soon-Jong ; Kim, Sun-Hwan ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 233~235
The kinetics of the 1,3-dipolar cycloaddition of p-substituted 3-phenylsydnones 1a-d with DMAD have been investigated. The reaction rates over a temperature range
were measured by UV spectrometry. The reactions found to be second-order overall, insensitive to the dielectric constants of the solvents, and characterized by a large entropy of activation. These findings are consistent with the rate-determining step involving the formation of cyclic transition state 1 and the reaction proposed to be concerted.
Stereoselective Synthesis of (7Z, 11E)-7, 11-Hexadecadien-1-yl Acetate, Sex Pheromone of the Angoumois Grain Moth
Kang, Suk-Ku ; Yoo, Kyung-Ok ; Moon, Hong-Sik ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 235~237
(7Z, 11E)-7, 11-Hexadecadien-1-yl acetate(1), the sex pheromone of the female Angoumois grain moth, Sitotroga cerealella, was synthesized via the acetylenic intermediate, (11E)-11-hexadecen-7-yn-ol THP ether(2). The acetylenic compound was prepared from 7-octyn-1-ol THP ether(4) and (3E)-1-bromo-3-octene(3). The (E)-homoallylic bromide 3 was synthesized by the Julia olefin synthesis of 1-cyclopropylpentan-1-ol(6).
Thermodynamic Analysis of the Hammett Reaction Parameter and Free Energy Relationship for the Pressure Change
Hwang, Jung-Ui ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 237~242
Pressure dependance of Hammett reaction parameter was analyzed and the free energy relationship for the pressure change derived thermodynamically. There are insufficient data in the literature to test the relation derived but from some limited previous data it could be concluded that the parameter
is dependent on pressure and increase or decrease as pressure increase for a given reaction series.
Competitive Photochlorination Reactions of Silane, di-Chloro and tri-Chlorosilanes at 337.1 nm
Jung, Kyung-Hoon ; Jung, Kwang-Woo ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 242~246
The hydrogen abstraction reactions of
by ground state chlorine atoms generated photochemically from chlorine molecules have been studied at temperatures between 15 and
The absolute rates for the reactions have been obtained by a competition technique using ethane as a competitor. The rate expressions (
) are found to conform to an Arrhenius rate law:
The activation energies obtained from this study represent the same trend as with the carbon analogues, while this trend was not found with respect to the bond dissociation energies among silicon compound homologues. These anomalous behaviors were interpreted in terms of electronic effects and of the structural differences between these compounds.
Palladium Catalyzed Carbonylative Vinylation of Aryl Halides with Olefins and Carbon Monoxide
Kim, Jin-Il ; Ryu, Cheol-Mo ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 246~250
The reaction of aryl iodides or bromides with olefins in the presence of 1 mol % of
and 3 equiv. of
in carbon monoxide atmosphere gave the corresponding aryl vinyl ketones in good yields with small amount of vinylated 1-aryl olefins. But, when the reaction was proceeded under the 10 atm of carbon monoxide, aryl vinyl
-diketones and aryl vinyl ketones were obtained in moderate to good yields. The reaction was tolerant of a wide variety of functional groups on either the aryl halides or olefin compounds. Reactivity of aryl halide decrease in the order; aryl iodide > aryl bromide
aryl chloride. In general, the reaction proceeded well and gave good yields of aryl vinyl ketones and aryl vinyl
-diketones when reactants are substituted with electron withdrawing groups.
Raman Spectroscopic Study of Benzonitrile on Silver Surface
Boo, Doo-Wan ; Kim, Kwan ; Kim, Myung-Soo ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 251~254
The surface-enhanced Raman scattering(SERS) of benzonitrile in a silver sol was investigated. It was concluded that the molecule adsorbed onto the silver surface via the nitrogen lone pair electrons. Using the surface selection rule, the orientation of the benzene ring with respect to the surface plane could not be determined conclusively. However, it seemed likely that benzonitrile is adsorbed edge-on to the surface. It was demonstrated that the SERS technique provides a useful method for detailed characterization of the chemisorbed layer.
Palladium Dichloro Complex Catalysed Oxidation of Cyclopentene by Dioxygen in Tetralin
Takehira, Katsuomi ; Hayakawa, Takashi ; Orita, Hideo ; Shimizu, Masao ; Oh, In-Hwan ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 254~257
Palladium dichloro complexes catalysed the oxidation of cyclopentene by dioxygen in tetralin solvent at ambient temperature. Cyclopentanone formed mainly together with autoxidation products from both cyclopentene and tetralin. The oxidation seems to proceed by co-oxidation mechanism, where tetralin was first oxidized to its hydroperoxide which then oxidized cyclopentene to cyclopentanone. Mechanism of the other by-products formations has been discussed.
Asymmetric Reduction of Prochiral
-Acetylenic Ketones With Potassium 9-0-(1,2 : 5,6-Di-O-isopropylidene-
Cho, Byung-Tae ; Park, Won-Suh ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 257~260
The asymmetric reduction of representative prochiral
-acetylenic ketones with a new chiral borohydride reducing agent, potassium 9-0-(1,2: 5,6-Di-O-isopropylidene-
-D-glucofuranosyl)-9-boratabicyclo[3.3.1]nonane, 1, in THF at
was studied. Structurally different acetylenic ketones such as internal
were chosen. Thus, the reduction of internal
-acetylenic ketones yields the corresponding propargyl alcohols, such as 67% ee for 3-hexyn-2-one, 75% ee for 5-methyl-3-hexyn-2-one, 86% ee for 5,5-dimethyl-3-hexyn-2-one, 74% ee for 3-nonyn-2-one and 61% ee for 4-phenyl-3-butyn-2-one. Terminal
-acetylenic ketones, such as 3-butyn-2-one, 1-pentyn-3-one, 4-methyl-1-pentyn-3-one and 1-octyn-3-one, are reduced to the corresponding alcohols with 59% ee, 17% ee, 44% ee and 12% ee of optical induction respectively. With one exception (4-methyl-1-pentyn-3-one), all propargyl alcohols obtained are enriched in R-enantiomers.
Benoxaprofen-photosensitization Decomposition of Tryptophan Peptides in Aqueous Micellar Systems
Yoon, Min-Joong ; Lee, Ki-Hwan ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 261~264
-methyl-5-benzoxazole acetic acid) is a nonsteroidal anti-inflammatory drug that causes acute cutaneous phototoxicity. The ability of benoxaprofen (BXP) and its photoproduct, decarboxybenoxaprofen (DBXP) to photosensitize the decomposition of tryptophan was evaluated in various media such as water, ethanol and aqueous micellar dispersions of surfactants. The weak photosensitization of BXP in water was found to be enhanced in cationic CTAB micelle system, but yielded little difference in anionic SDS micelles. In ethanol solution, BXP was determined to photosensitize the decomposition of tryptophan, but no photosensitization was observed with DBXP. All of these results implicate that the anion radical of BXP may play a major role in the photosensitization in hydrophobic micellar phase, forming superoxide through interaction with oxygen as demonstrated by observation that the photosensitization was inhibited by superoxide dismutase.
Cationic Cyclization to Tricyclene Structures
Kang, Ja-Hyo ; Lee, Won-Koo ; Shin, Hyun-Tai ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 264~269
Various carbocation-mediated cyclizations to tricyclene structure (basically, tricyclo
heptane skeleton) were carried out, starting from protonated species of either 3-methyl-2,5-norbornadiene-2-carboxylic acid (10) or 3-methylene-5-norbornene-2-carboxylic acids (18 and 19). The resulting products were individually converted to
-iodotricyclene (35), a pivotal intermediate in almost all syntheses of tricyclene terpenes.
Synthesis of 1,1-Dichloro-2,3,4,5-Tetraphenyl-1-Silacyclopenta-2,4-diene and Its Reaction with Alkali Metal: Evidence for the Formation of Silylanion
Joo, Wan-Chul ; Park, Yoon-Chang ; Kang, Suk-Ku ; Hong, Jang-Hwan ; Kong, Young-Kun ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 270~272
1,1-Dichloro-2,3,4,5-tetraphenyl-1-silacyclopenta- 2,4-diene was synthesized through the reaction of
with 1,4-dilithiotetraphenylbutadiene in 50% yield. From the reaction of this silole with metal, an air sensitive red-brownish solid was obtained. Treatment of this reaction product with
gave 1,1-dimethyl-2,3,4,5-tetraphenyl-1-silacyclopenta- 2,4-diene and 1,1-bis(trimethylsilyl)-2,3,4,5-tetraphenyl-1-silacyclopenta-2,4-diene, respectively. From these results, the formation of reactive 2,3,4,5-tetraphenyl-1-silacyclopenta-2,4-dienyl dianion was confirmed.
New Polyacetylene Compounds from Panax Ginseng C. A. Meyer
Shim, Sang-Chul ; Chang, Suk-Ku ; Hur, Chan-Woo ; Kim, Chang-Kew ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 272~275
Two polyacetylene compounds having diyn-ene chromophore were isolated from fresh Korean ginseng roots through solvent fractionation, partition and silica gel column chromatography. The low pressure semi-preparative liquid chromatography and high performance preparative liquid chromatography were used for final separation of polyacetylenic fractions. The chemical structures of these polyacetylenes were determined to be heptadeca-1,8-dien-4,6-diyn-3,10-diol and heptadeca-1,4-dien-6,8-diyn-3,10-diol by UV, FT-IR,
mass spectra and elemental analysis.
Addition Compounds of Alkali Metal Hydrides. 32. A Comparison Study of Chiral Trialkylborohydrides and Chiral Dialkylmonoalkoxyborohydrides for the Asymmetric Reduction of Prochiral Ketones: The Effect of Comparable Chiral Alkyl and Alkoxy Groups on Asymmetric Industion
Brow, Hervert C. ; Park, Won-Suh ; Cho, Byung-Tae ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 276~280
Several chiral potassium B-alkyl-9-boratabicyclo[3.3.1]nonanes
and potassium B-alkoxy-9-boratabicyclo[3.3.1]nonanes
were synthesized by treatment of the corresponding trialkylboranes and dialkylmonoalkoxyboranes with a small excess of potassium hydride. The chiral B-alkoxy derivatives generally reduce representative ketones, such as acetophenone and 3-methyl-2-butanone, with greater optical induction than the corresponding B-alkyl derivatives, suggesting the involvement of the oxygen atom in the control process for asymmetric synthesis.
Chemical Modification of Glycolate Oxidase from Spinach by Diethyl Pyrocarbonate. Evidence of Essential Histidine for Enzyme Activity
Lee, Kun-Kook ; Kim, Hong-Sun ; Choi, Jung-Do ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 280~285
FMN-dependent glycolate oxidase from spinach is inactivated by diethyl pyrocarbonate at pH 7.0. Inactivation of both apo- and holoenzyme by diethyl pyrocarbonate follows pseudo-first-order kinetics and first order with respect to the reagent. A series of difference spectra of inactivated and native enzymes show a single peak at 240 nm, indicating the modification of histidyl residues. No decrease in absorbance at around 280 nm due to formation of O-carbethoxytyrosine is observed. The rate of inactivation is dependent on pH, and the data for pH dependent rates implicate the involvement of a group with a pKa of 6.9. The activity lost by treatment with diethyl pyrocarbonate could be almost fully restored by incubation with 0.75M hydroxylamine. The reactivation by hydroxylamine and the pH dependence of inactivation are also consistent with that the inactivation is due to modification of histidyl residues. Although coenzyme FMN is without protective effect, the substrate glycolate, the product glyoxylate, and two competitive inhibitors, oxalate and oxalacetate, provide marked protection against the inactivation of the holoenzyme. These results suggest that the inactivation of the oxidase by diethyl pyrocarbonate occurs by modification of essential histidyl residue(s) at the active site.
Reducing Characteristics of Potassium Triethylborohydride
Yoon, Nung-Min ; Yang H.S. ; Hwang, Y.S. ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 285~291
The approximate rates, stoichiometries and products of the reaction of potassium triethylborohydride
with selected organic compounds containing representative functional groups under the standard condition
THF) were examined in order to explore the reducing characteristics of this reagent as a selective reducing agent. Primary alcohols, phenols and thiols evolve hydrogen rapidly whereas secondary and tertiary alcohols evolve very slowly. n-Hexylamine is inert to this reagent. Aldehydes and ketones are reduced rapidly and quantitatively to the corresponding alcohols. Reduction of noncamphor gives 3% exo- and 97% endo-norboneol. Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-dihydroxyanthracene stage. Carboxylic acids liberate hydrogen rapidly and quantitatively but further reduction does not occur. Anhydrides utilize 2 equiv of hydride to give an equimolar mixture of acid and alcohol. Acid chlorides, esters and lactones are rapidly and quantitatively reduced to the corresponding alcohols. Epoxides are reduced at moderate rates with Markovnikov ring opening to give the more substituted alcohols. Primary amides liberate 1 equiv of hydrogen rapidly. Further reduction of caproamide is slow whereas benzamide is not reduced. Tertiary amides are reduced slowly. Benzonitrile utilizes 2 equiv of hydride in 3 h to go to the amine stage whereas capronitrile takes only 1 equiv. The reaction of nitro compounds undergo rapidly whereas azobenzene and azoxybenzene are reduced slowly. Cyclohexanone oxime rapidly evolves hydrogen without reduction. Phenyl isocyanate utilizes 1 equiv of hydride to proceed to formanilide stage. Pyridine N-oxide and pyridine is reduced rapidly. Disulfides are rapidly reduced to the thiol stage whereas sulfoxide, sulfonic acid are practically inert to this reagent. Sulfones and cyclohexyl tosylate are slowly reduced. Octyl bromide is reduced rapidly but octyl chloride and cyclohexyl bromide are reduced slowly.
Vibrational Spectroscopic Study of Benzenethiol on Silver Surface
Yi, Whi-Kun ; Park, Cheol-Woo ; Kim, Myung-Soo ; Kim, Kwan ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 291~296
Vibrational spectroscopy has been applied to the benzenethiol molecule adsorbed on the silver surface. The results of infrared and Raman spectral studies have led to the conclusion that benzenethiol is chemisorbed dissociatively on the silver surface by rupture of S-H bond and the benzenethiolate formed upon adsorption is bound to silver via its sulfur atom. It seemed more likely that benzenethiol is adsorbed as being inclined to the silver surface. On contact with oxygen, the geometry of the adsorbed species appeared to bear a resemblance to that of silver benzenethiolate salt. The infrared bands of adsorbed species remained with little decrease of intensity even after the prolonged evacuation at 673 K, indicating that benzenethiol is very strongly chemisorbred to the silver surface.
Photochemical Rearrangement of Chloranil
Kim, Sung-Sik ; Yoo, Dong-Yeol ; Cho, In-Ho ; Shim, Sang-Chul ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 296~298
Irradiation of a solution of chloranil and cycloheptatriene, or 1,3-cyclohexadiene, in dichloromethane yielded unexpected photorearrangement products as the major product, while chloranil with cyclohexene gave the photorearrangement product as well as 1 : 1 adduct.
Theoretical Studies on the Photocycloaddition Reaction of Psoralen with Thymidine
Kim, Ja-Hong ; Oh, Se-Woung ; Lee, Yoon-Sup ; Shim, Sang-Chul ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 298~300
The theoretical studies on the photocycloaddition reaction of 5,7-dimethoxycoumarin and 4',5'-dihydropsoralen with thymidine were carried out as a model for photosensitizing reaction of psoralen with DNA. The results are in reasonable agreement with experimental observations. The photoadducts between dimethoxycoumarin and thymidine were predicted to be
-cycloadducts through the cycloaddition of 3,4-pyrone double bond of dimethoxycoumarin to 5,6 double bond of thymidine. The major photoadduct of 4',5'-dihydropsoralen with thymidine has the anti head-to-head stereochemistry.
Partial Reduction of Nitriles to Aldehydes by Thexylbromoborane-Methyl Sulfide
Cha, Jin-Soon ; Oh, Se-Yeon ; Kim, Jin-Euog ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 301~304
A systematic study of the partial reduction of nitriles to the corresponding aldehydes with thexylbromoborane-methyl sulfide
under practical conditions has been carried out. The yields of aldehydes are good in the aliphatic series. However, the yields of aromatic series vary with substituents and ring itself.
Reaction of Di-s-butoxyborane in Tetrahydrofuran with Selected Organic Compounds containing Representative Functional Groups. Catalytic Effect of Tetraalkoxyborate on the Reaction of Dialkoxyborane
Cha, Jin-Soon ; Lee, Jae-Cheol ; Kim, Jin-Euog ; Lee, Kwang-Woo ; Yoon, Mal-Sook ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 304~310
The approximate rate and stoichiometry of the reaction of excess di-s-butoxyborane with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran,
were examined in order to define the characteristics of the reagent for selective reductions. And the catalytic effect of lithium tetra-s-butoxyborate on the reaction of di-s-butoxyborane was also studied in order to increase the utility of this reducing system. Di-s-butoxyborane reacts only with simple aldehydes. However the addition of 2.5 mole % of lithium tetra-s-butoxyborate shows the tremendous rate enhancement of reaction for aldehydes, ketones, anhydrides, acid chlorides, lactones, and epoxides. This catalytic effect is assumed to in situ formation of lithium trialkoxyborohydride.
A Facile Synthesis of Propellanes via Dianion Chemistry
Jun, Jong-Gab ; Mundy, Bradford P. ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 310~313
A dianion-mediated dialkylation reaction provides a variety of propellanes. 12-Thia[4.4.3] propel-3-ene, 3-(N-benzyl)-2,4-dioxotricyclo[18.104.22.168] decane and 3-(N-benzyl)-2,4-dioxotricyclo[22.214.171.124] nonane were prepared by this dianion ring annulation methodology.
Raction of Thexylbromoborane-Methyl Sulfide in Methylene Chloride with Selected Organic Compounds Containing Representative Functional Groups
Cha, Jin-Soon ; Kim, Jin-Euog ; Oh, Se-Yeon ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 313~318
The approximate rate and stoichiometry of the reaction of excess Thexylbromoborane-methyl sulfide,
with selected organic compounds containing representative functional groups under standardized conditions (methylene chloride,
were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The selectivity of the reagent was also compared to the selectivity of thexylchloroborane-methyl sulfide. Thexylbromoborane appears to be a much milder and hence more selective reducing agent than thexylchloroborane. The reagent tolerates many organic functionalities. Thus, the reagent shows very little reactivity or no reactivity toward acid chlorides, esters, epoxides, amides, nitro compounds including simple olefins. However, this reagent can reduce aldehydes, ketones, carboxylic acids, nitriles, and sulfoxides. Especially the reagent reduces carboxylic acids including
-unsaturated ones and nitriles to the corresponding aldehydes. In addition to that, thexylbromoborane shows good stereoselectivity toward cyclic ketones, much better than the chloro-derivative.
Non-Newtonian Intrinsic Viscosities of Biopolymeric and Nonbiopolymeric Solutions (I)
Jang, Chun-Hag ; Kim, Jong-Ryul ; Ree, Tai-Kyue ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 318~324
Experimental results for viscous flow of poly (
-methyl L-glutamate) solutions have been published elsewhere. The data of
are expressed by the following equation,
are the intrinsic viscosity at shear stress f and zero, respectively,
viscosity of the solvent,
is the relaxation time of flow unit 2,
is a constant related to the elasticity of flow unit 2. The theoretical derivation of Eq.(A1) is given in the text. The experimental curves of
vs. log f are compared with the theoretical curves calculated from Eq.(A1) with good results. Eq.(A1) is also applied to non-biopolymeric solutions, and it was found that in the latter case
The reason for this is explained in the text. The problems related to non-Newtonian flows are discussed.
Catalytic Reactions of 3-Phenyl-2-propen-1-ol with Perchloratocarbonylbis (triphenylphosphine) rhodium (I)
Park, Jeong-Han ; Chin, Chong-Shik ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 324~328
Reaction of Rh
(1) with trans-
(2) produces a new cationic rhodium(Ⅰ) complex,
(3) where 2 is coordinated through the oxygen atom but not through the olefinic group. At room temperature under nitrogen, complex 1 catalyzes dehydrogenation, hydrogenolysis, and isomerization of 2 to give
= CHCHO (4), trans-
(6), respectively, and oligomerization of 2 whereas under hydrogen, complex 1 catalyzes hydrogenation of 2 to give
(7) and hydrogenolysis of 2 to 5 which is further hydrogenated to
(8). The dehydrogenation and hydrogenolysis of 2 with 1 suggest an interaction between the rhodium and the oxygen atom of 2, whereas the isomerization and hydrogenation of 2 with 1 indicate an interaction between the rhodium and the olefinic system of 2.
Palladium-Catalyzed Cross-Coupling Reaction of (E)-1-Alkenyl-1,3,2-benzo-dioxaboroles with Allylic Phenoxides. A Simple Route 1,4-Alkadienes from Alkynes via Hydroboration
Sasaya Fumihito ; Norio Miyaura ; Akira Suzuki ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 329~332
The reaction of (E)-1-alkenyl-1,3,2-benzodioxaboroles with a variety of allylic phenoxides in the presence of a catalytic amount of Pd
is described. The reaction affords a general and simple procedure for the preparation of 1,4-alkadienes from alkynes via hydroboration.
Non-Newtonian Intrinsic Viscosities of Biopolymeric and Non-biopolymeric Solutions (II)
Jang, Chun-Hag ; Kim, Chang-Hong ; Ree, Taik-Yue ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 332~335
This paper is a continuation of our previous
and deals with Eq.(1) (see the text), which was theoretically derived in the
is the intrinsic viscosity at stress f and f = O, respectively. Equation (1) predicts how
changes with stress f, relaxation time
of flow unit 2 and a constant
related with the elasticity of molecular spring of flow unit 2. In this paper, Eq.(1) is applied to a biopolymer, e.g., poly (
-benzyl L-glutamate), and nonbiopolymers, e.g., polyisobutylene, polystyrene, polydimethylsiloxane and cellulose triacetate. It was found that the
factor is zero for non-biopolymers while
for biopolymers as found
Because of the non-Newtonian nature of the solutions, the ratio
drops from its unity with increasing f. We found that the smaller the
the larger the
at which the viscosity ratio drops from the unity, vice versa.
An Effective Acylation of Cephalosporins Using 1-Methanesulfonyloxy-6-trifluoromethylbenzotriazole
Lee, Cheol-Hae ; Moon, Chi-Jang ; Kim, Kyeong-Sook ; Kim, Jae-Hak ; Kim, Dae-Whang ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 336~338
A new coupling agent, 1-methanesulfonyloxy-6-trifluoromethyl-benzotriazole (3), was prepared by the reaction of 1-hydroxy-6-trifluoromethylbenzotriazole (1) and methanesulfonyl chloride. 3 was reacted with 2-(2-amino-4-thiazolyl)-2-synalkoxyi minoacetic acid (4) to give a mixture of active intermediates (5 and 6), which was treated with 7-aminocephalosporanic acid derivatives (10) to afford cephalosporin derivatives (11) in short reaction time with high yields.
Remarks on Single-Frequency Two-Photon Absorption
Lee, Duck-Hwan ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 338~340
The single-frequency two-photon absorption tensor is carefully rederived and examined. It is pointed out that the conventionally used tensor, which has been formally deduced from the different-frequency two-photon absorption tensor, can give an incorrect absolute two-photon absorption rate. The identity forbidded selection rule and the polarization ratio expressions are also examined with the new tensor.
Photophysical properties of Khellin
Shim, Sang-Chul ; Kang, Ho-Kwon ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 341~344
The fluorescence quantum yield of khellin is sensitive to temperature and to the nature of solvents, especially the proton-donating ability in solute-to-solvent hydrogen bonding. The intersystem crossing quantum yields are 0.4 and 0.15 in acetonitrile and ethanol, respectively. The fluorescence quantum yields in ethanol and isopentane at 77 K are 0.61 and 0.07, respectively, both of which are much larger than the values at room temperature. The phosphorescence lifetime is relatively long and decreases with decreasing solvent polarity. The phosphorescence to fluorescence quantum yield ratio is very small and remains unchanged in various solvents. The results suggest that internal conversion is an important decay channel of the excited singlet state of khellin, especially in the hydrogen-bonding hydroxyl solvents.
Vibrational Spectroscopic Study of Benzenethiol Adsorbed on
Yi, Whi-Kun ; Park, Cheol-Woo ; Kim, Myung-Soo ; Kwan, Kim ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 345~346
Phototransformation of the Phytochrome-Cyclic AMP and Phytochrome-Estriol Complexes
Kim, Hak-Yong ; Quae, Chae ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 347~348
Substituent Effects on the Hydration Reactions of Didhydronicotinamides
Koh Park, Kwang-Hee ; Yoo, Jae-Gug ; Park, Joon-Woo ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 348~349
Resonance Shunt' Phenomenon in Nucleophilic Substitution of
-Carbonyl Derivatives Demonstrated by the Cross Interaction Constants
Lee, Ikc-Hoon ; Shim, Chang-Sub ; Chung, Soo-Young ; Lee, Hai-Whang ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 350~351
A Convenient Synthesis of (E)-
Kang, Suk-Ku ; Chung, Gyung-Yun ; Lee, Dong-Ha ;
Bulletin of the Korean Chemical Society, volume 8, issue 4, 1987, Pages 351~353