• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.487-490
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• 2008

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1307-1308
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• 2004

• Applied Biological Chemistry
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• v.45 no.4
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• pp.223-227
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• 2002

Characteristic stereostructures of farnesyl protein transferase (FPTase) inhibition materials isolated from Artemisia sylvatica and regioselectivity of biogenic Diels-Alder reactions between dehydromatricarin molecules A and B were examined quantitatively. Results revealed that the major reaction of frontier molecular orbital (FMO) interaction proceeds through charge-control reaction between LUMO of A16, dienophile and HOMO of B1, diene, and the isolated 8-acetylarteminolide and artanomaloide were minor products. FPTase inhibition activity and hydrophobicity of 8-acetylarteminolide were $pI_{50}=3.75$ and logP=2.62, respectively. FPTase inhibition activity of 8-acetylarteminolide was higher than those of artanomaloide and dehydromatricarin.

• Journal of the Korean Chemical Society
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• v.23 no.5
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• pp.286-295
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• 1979

In order to predict the effect of Lewis acid catalysis on the regioselectivity of the Diels-Alder reactions between unsymmetrically substituted dienes and dienophiles, the frontier orbital theory applied to the theoretical model of the Lewis acid complexed dienophile was studied by means of CNDO/2 MO. In the majority of reactions, CNDO/2 calculations gave good results in accordance with experimental orientation. Also, it was shown that the secondary orbital interaction played an important role in the regioselectivity of the Diels-Alder reaction between unsymmetrically substituted dienes and dienophiles. Although ANH's treatment is mathematically simpler than other methods, ANH's method which laid emphasis on dissymmetrical transition state gave good results on decision of regioselectivity.

• Journal of Applied Biological Chemistry
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• v.48 no.2
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• pp.97-100
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• 2005

Chiral dienophile 5 was synthesized from D-glucose by consecutive diisopropylidenation, partial deprotection, diol cleavage, and Wittig reactions. Under thermal conditions, asymmetric Diels-Alder reaction between chiral dienophile and cyclopentadiene gave four possible chiral norbornenes stereoisomers whose absolute configurations were determined through CADD and NMR.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.289-290
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• 2009

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.128-131
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• 2017

We explore the inverse electron demand Diels-Alder reactions of tetrazines with various functional groups employing quantum calculations. In general, the rate of inverse electron demand Diels-Alder reaction depends on molecular orbital levels of electron donor and electron acceptor. Likewise, ${\pi}$ orbital of the dienophile and ${\pi}^*$ orbital of the diene is a key factor. In this work, we discuss the case where the energy of diene's ${\pi}^*$ molecular orbital is not the sole governing factor to determine the reaction rate, rather the rate shows strong correlation with the charge density of dienes.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1679-1684
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• 2011

Interfacial reactions kinetics often differ from kinetics of bulk reactions. Here, we describe how the density change of an immobilized reactant influences the kinetics of interfacial reactions. Self-assembled monolayers (SAMs) of alkanethiolates on gold were used as a model interface and the Diels-Alder reaction between immobilized quinones and soluble cyclopentadiene was used as a model reaction. The kinetic behavior was studied using varying concentrations of quinones. An unusual threshold density of quinones (${\Gamma}_c$ = 5.2-7.2%), at which the pseudo-first order rate constant started to vary as the reaction progressed, was observed. This unexpected kinetic behavior was attributed to the phase-separation phenomena of multi-component SAMs. Additional experiments using more phase-separated two-component SAMs supported this explanation by revealing a significant decrease in ${\Gamma}_c$ values. When the background hydroxyl group was replaced with carboxylic or phosphoric acid groups, ${\Gamma}_c$ was observed at below 1%. Also, more phase-separated thermodynamically controlled SAMs produced a lower critical density (3% < ${\Gamma}_c$ < 4.9%) than that of the less phaseseparated kinetically controlled SAMs (6.5% < ${\Gamma}_c$ < 8.9%).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.2 s.344
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• pp.13-17
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• 2006

Pentacene channel for organic thin film transistor was deposited on the SiOC film by thermal evaporation. The growth of pentacene is related with the Diels-Alder reaction and the nucleophilic reaction by the thermal induction. The surface is an important factor to control the recursive Diels-Alder reaction for growing of pentacene on SiOC far The terminal C=C double bond of pentacene molecule was broken easily as a result of attack of the nucleophilic reagents on the surface of SiOC film. The nucleophilic reaction can be accelerated by increasing temperature on surface, and it maks pentacene to grow hardly on the SiOC film with a flow rate ratio of $O_2/(BTMSM+O_2)=0.5$ due to its inorganic property. The nucleophlic reaction mechanism is $SN_2(bimolecular nucleophilic substitution)$ type.

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.676-681
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• 1994

Diels-Alder adducts, carbacephems were obtained when 4-acetoxyazetidine-2-one or (3R,4R)-4-acetoxy-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]azetidin-2-one was reacted with 2-(tert-butyldimethylsilyloxy)-1,3-butadiene or with 3-(tert-butyldimethylsilyloxy)-1,3-pentadiene. When tert-butyldiemethylsilyl acrylate was used as the diene, products in which was acetoxy group of 4-acetoxyazetidin-2-one derivatives was substituted by an acryloyloxy group were isolated. When the same reaction was carried out with 4-phenylsulfonylazetidin-2-one as a dienophile with 2-(tert-butyldimethylsilyloxy)-1,3-butadiene, 4-phenylsulfoyl-2-butanone was obtained instead of the expected carbacephem. When dimeric form of thiochalcone was reacted with 4-acetoxyazetidin-2-one in the presence of zinc chloride, the $\beta-lactam$ ring of the azetidin-2-one was destructed and no product was isolated. Also, the reaction of 2-trimethylsilyloxy-1-aza-1,3-butadiene, which was obtained from N-methylacrylamide by treatment of trimethylsilyl trifluoromethanesulfonate in the presence of triethylamine, with 4-acetoxyazetidin-2-one did not give any products.