• Bulletin of the Korean Chemical Society
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• v.18 no.2
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• pp.164-170
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• 1997

Via hydrosilation-alkenylation approach using hydrosilanes (HSiMeCl2 and HSiCl3) and allylmagnesium bromide with siloxane tetramer (MeCH2=CHSiO)4 as core molecule, noble carbosilane dendrimers with 12, 24, 48 and 96 allylic end groups have been prepared. The reaction path of the repetitive alkenylation and hydrosilation was monitored by means of NMR spectroscopic measurements. Every step for the formation of dendrimer provided almost quantitative yields as pure dendrimers. Based on the observation of UV spectroscopic measurements of Gn (n=1-4) molecules containing allylic end groups, the maximal molal absorption coefficients (εmax) at λmax and the number of double bonds proved an exponentially increased correlation.

• Journal of the Korean Chemical Society
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• v.39 no.10
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• pp.789-798
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• 1995

The silanedendrimer with 64 allylic end groups was prepared via a divergent growth approach. The reaction path of the repetitive alkenylation and hydrosilylation cycles was monitored by NMR spectroscopic analysis. Each of the two steps provided almost quantitative yields of pure dendrimers.

• Journal of the Korean Chemical Society
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• v.39 no.10
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• pp.799-805
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• 1995

Silane dendrimer with 96 allylic end groups has been synthesized in excellent yield using repetitive alkenylation-hydrosilylation cycles. Each of the two steps provided the products in almost quantitative yields. After a simple chromotograpic purification (silica gel, chloroform), pure dendrimers were obtained and their purity was checked with 1H, 13C NMR spectroscopic method and elemental analysis.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.669-675
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• 2002

The alkenylation of o-xylene with 1,3-butadiene to make OTP(ortho-tolyl Pentene) was carried out over liquid phase NaK alloy, Na metal and the metallic sodium dispersed on the specific support such as NaX and $Al_2O_3$. Liquid phase NaK alloy showed the improved conversion and selectivity when they were pretreated by ultrasound to increase the dispersion. For the case of metallic sodium, the induction period for the formation of homogeneous metal sodium solution with high dispersion was needed before the reaction. In the case of metallic sodium dispersed on support, more than 80 % conversion could be obtained without induction period regardless of supports used. But 85 % of the metallic sodium was resolved into the reaction mixture after reaction for 7 hours. The amount of byproducts, oligomers, produced from OTP and 1,3-butadiene increased with the amount of 1,3-butadiene introduced and the selectivity to OTP was in inversely proportional to the conversion.

• Bulletin of the Korean Chemical Society
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• v.17 no.5
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• pp.419-424
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• 1996

A dendrimeric silane containing 162 allylic end groups is prepared via a divergent growing approach. The reaction process of the repetitive alkenylation and hydrosilylation cycles was monitored by NMR spectroscopic attachments. Both steps provided almost quantitative yields of pure silane dendrimers.

• Journal of the Korean Chemical Society
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• v.42 no.3
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• pp.277-284
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• 1998

Dendritic macromolecules of the first to fourth generation were synthesized, using alkenylation and hydrosilation cycles with allylmagnesium bromide and dichloromethylsilane as building blocks and siloxane tetramer $(Me(CH_2=CH)SiO)_4$, as core molecule. By the reaction of the dichloromethylsilyl-capped generation (G4P) with p-bromophenol, p-phenylphenol and lithium phenyethynylide, dendrimers with specific functions (G4P-BP (Mw: 16,300), G4P-PP (16,121), and CAP-PA (11,764)) have been produced. Analysis of new dendrimers by NMR, UV and MALD1 mass spectrometry suggests that they are pure and unified.

• Bulletin of the Korean Chemical Society
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• v.17 no.7
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• pp.592-595
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• 1996

A silane dendrimer with 48 allylic end groups has been synthesized in excellent yield, via repetitive alkenylation-hydrosilation cycles. Starting with hexaallylethylenedisilane ((CH2=CHCH2)3SiCH2)2 as the core molecule (G0), a succession of alternate platinum catalyzed hydrosilation (Pt/C, 10% platinum content on active carbon) of all allyl groups with methyldichlorosilane and the allylation of all SiCl2 groups with allylmagnesium bromide in THF provided 3rd generation (G3) as carbosilane dendrimer. All the generations of dendrimer have been characterized by 1H and 13C NMR spectroscopy as well as elemental analysis.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.286-290
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• 2006

Rapid and facile syntheses of N-alkenyl lactam series via condensation between lactams and a variety of aldehydes such as n-propanal, isobutanal, n-butanal, n-hexanal, n-octanal and phenylacetaldehyde were studied under microwave or conventional heating. Various solid catalysts and solvents were examined to maximize the yields of condensation reactions.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.871-877
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• 2005

Recent progress in the filed of transition-metal mediated C-H bond activation has had a great influence on organic synthesis. Among such transition-metal catalyzed reactions, ortho-functionalization via the chelationassisted strategy has been paid great attentions as one of the powerful methodologies for converting aromatic compounds into ones that are more functionalized at the exclusively ortho-position. In this context, various transition metal-catalyzed ortho-functionalizations such as alkylation, alkenylation, silylation and carbonylation are described briefly and their prospects are suggested.

• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.393-400
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• 1999

Dendritic carbosilanes based on hyperbranched polycarbosilanes as core molecule have been prepared The core molecules were obtained by the use of hydrosilation of $HSiMe_{3-n}$$(CH_2CH=CH_2)_n$(n=2; $AB_2$,3;$AB_3$type). The hyperbranched core $AB_2\;and\; AB_3$ type polymers were generated to higher molecular dendritic carbosilanes Gn+1 by the use of hydrosilation and alkenylation sequence. The Gn+2P generations were not obtained as unified molecules by the use of hydrosilation with $HSiMeCl_2$. Gn and Gn+1 type polymers were produced to polysilol by the reaction of 9-BBN and alkali medium oxidation of hydroborated compounds. The degree for reaction has been controlled by the NMR spectroscopy.