• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2711-2718
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• 2012

The alkylation of the ambident enolates of a methyl glycinate Schiff base with ethyl chloride was studied at B3LYP and MP2 levels with $6-31+G^*$ basis set. The free (E)-enolates and (Z)-enolate are similar in energy and geometry. The transition states for the alkylation of the free (E)/(Z)-enolate with ethyl chloride have similar energy barriers of ~13 kcal/mol. However, with a lithium ion, the (E)-enolate behaves as an ambident enolate and makes a cyclic lithium-complex in bidentate pattern which is more stable by 11-23 kcal/mol than the (Z)-enolate-lithium complexes. And the TS for the alkylation of (E)-enolate-lithium complex coordinated with one methyl ether is lower in energy than those from (Z)-enolate-lithium complexes by 4.3-7.3 kcal/mol. Further solvation model (SCRF-CPCM) and reaction coordinate (IRC) were studied. This theoretical study suggests that the alkylation of ambident enolates proceeds with stable cyclic bidentate complexes in the presence of metal ion and solvent.

• Journal of the Korean Applied Science and Technology
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• v.16 no.2
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• pp.117-125
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• 1999

The alkylation benzene with 1-dodecene of Mordenite, Zeolite ${\beta}$ and Zeolite Y was studied in the stirring batch reactor. The kinds of zeolites were found to have influenced the reaction conversion and distribution of phenyldodecane isomer in the product. Compared to the alkylation conducted over Zeolite Y and Zeolite ${\beta}$, the alkylation over Mordenite exhibited higher distribution of 2-phenyldodecane and the alkylation conducted over Zeolite Y and Mordenite, the alkylation over Zeolite ${\beta}$ exhibited higher distribution of heavy alkylate which formed through oligomerization reaction readily deactivated the Lewis acid sites. A special feature of the effect of the benzene to 1-dodecene ratio the reaction conversion and selectivity of phenyldodecane isomer was found. At alkylation of benzene with 1-dodecene over Zeolite ${\beta}$, when the catalyst content in the system was high, the reaction will reach the optimal conversion at the higher B/D. When the benzene to 1-dodecene ratio was high, the selectivity of phenyldodecane isomer is high. It was also found that at the similar reaction conversion there was the same product distribution regardless of D/C ratio.

• Polymer(Korea)
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• v.38 no.4
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• pp.496-501
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• 2014

Polyalphaolefin (PAO) is a synthetic lubricant that is superior to mineral-based lubricants in terms of physical and chemical characteristics such as low pour point (PP), and high viscosity index (VI). This paper first reports a novel preparation route for a synthetic lubricant via alkylation of isoparaffins using a peroxide initiator without olefin. Alkylation of three kinds of isoparaffins such as i-$C_{16}$, i-$C_{18}$, and i-$C_{23}$ as well as alkylation of i-$C_{18}$ with 2-pentene using di-tert butyl peroxide initiator were conducted under various conditions to confirm alkylation reaction from isoparaffins themselves i.e; Single-molecule alkylation. Various properties of each alkylates (VI and PP) were investigated as a synthetic lubricant. Single-molecule alkylation made from i-$C_{16}$ a,nd i-$C_{18}$ showed ultra high VI (>140) and low PP (< $-30^{\circ}C$).

• Archives of Pharmacal Research
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• v.15 no.4
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• pp.304-308
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• 1992

The alkylation of resorcinol with cyclic allylic alcohol in non-aqueous acid medium gives intermolecular Friedel-Craft compounds. The products are primary alkylation products. The likage always occurs between carbon 3 of cyclic allylic alcohol and the position 2, 4, 5 or 6 of the resorcinol.

• Journal of Integrative Natural Science
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• v.1 no.3
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• pp.189-191
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• 2008

Alkylation, carbonylation and cyclization reaction using transition metal(or inner-) complexes as reducing agents or catalysts were investigated.

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.69-72
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• 2004

The N-alkylation of 4-aminopyrimidine with a tetrahydro-3-aza-cyclopropa[c]inden-5-one, which is a model reaction of the pharmacophore of duocarmycins, was studied with a quantum chemical method. We consider two factors for the acceleration of the N-alkylation; distortion and protonation of the model pharmacophores. The distortion of the spirocyclopropyl moiety in the model spirocyclopropylcyclohexadienone could induce an intrinsic energy of 3-4 kcal/mol, but the protonation on the carbonyl oxygen of the model cyclohexadienone lowers the transition energy of the N-alkylation of 4-aminopyrimidine dramatically (~46 kcal/mol) and is considered to play a major role in the enzyme reaction. The distorted and protonated spirocyclohexadienone is exothermally relieved to a phenol with the heat of reaction of -37 kcal/mol. The protonation process is proposed to be the mode of action of duocarmycins in the DNA alkylation.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.385-390
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• 1998

Adozelesin and carzelesin are synthetic analogues of the extremely potent antitumor antibiotic CC-1065, which alkylates N3 of adenine in a consensus sequence $5^1$-(A/T)(A/T)$A^*$ ($A^*$ is the site of alkylation). We have investigated the DNA sequence selectivity of adozelesin and carzelesin by thermally ind ced DNA strand cleavage assay using radiolabeled restriction DNA fragments. An analysis of alkylation patterns shows that the consensus sequences for carzelesin and adozelesin have been found to be $5^1$-(A/T)(A/T)$A^*$ and $5^1$-(A/F)(G/C)(A/T)$A^*$. A new consensus sequence, $5^1$-(A/T)(A/T)$CA^*$, has been observed to display an additional alkylation site for adozelesin but not for carzelesin. These results indicate that the pattern of sequence selectivity induced by carzelesin is similar but not identical to those induced by adozelosin.

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1213-1221
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• 2002

Friedel-Crafts alkylation reaction of an isomeric mixture of 1,2,3,4,5,6,7,8- (2) and 1,2,3,4,5,6,7,8-octahydrophenanthrene (2') with excess vinylchlorosilanes such as vinyl(methyl)dichlorosilane (1a) and vinyltrichlorosilane (1b) in the presence of aluminum chloride catalyst at 80 $^{\circ}C$ gives only one dialkylated products, 9,10-bis[2-(chlorosilyl)ethyl]-1,2,3,4,5,6,7,8-octahydroanthrenes [(Cl2XSiCH2CH2)2C14H16: X = Me (4a), Cl (4b)] in good yields, but 9,10-bis[2-(chlorosilyl)ethyl]-1,2,3,4,5,6,7,8-octahydrophenanthrenes are not obtained. However, monoalkylation of 2 with 1 affords a mixture of both isomeric compounds, 9-[2-(chlorosilyl)ethyl]-1,2,3,4,5,6,7,8-octahydroanthracenes 3 and -phenanthrenes 3'. The yield of product 3' is always higher than that of 3. When a mixture of 3 and 3' is alkylated again with 1, only product 4 without phenanthrene type compounds is obtained, indicating that the isomerizations between 2 and 2', or 3 and 3'occur under the alkylation condition. The alkylation with dimethylvinylchlorosilane or trimethylvinylsilane did not proceed. The structure of 4a is determined by X-ray single crystal diffraction analysis.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.587-593
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• 2011

As a result of increasing environmental concerns related to air quality and maintenance of automobiles, the alkylation of isobutane with olefins has become an even more important process for production of high quality gasoline. However, the widespread use of the alkylation process is limited by the polluting and corrosive liquid acid catalysts (HF and $H_2SO_4$) currently used in industry. For the reason, a large number of solid catalysts, especially zeolites, have been studied as an environmental friendly catalyst in this process. Recently, mesoporous solid acids and ionic liquids have been investigated as a green catalyst. In this review, the research of environmental friendly catalysts for an isobutane alkylation is summarized.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2935-2937
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• 2009

Asymmetric glycolate alkylation reactions in the solid phase were investigated for the first time with good stereoselectivities being obtained by using a Wang resin supported 2-imidazolidinone chiral auxiliary.