• Title/Summary/Keyword: N-Alkenylation

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Preparation of Carbosilane Dendrimers Based on Siloxane Tetramer: Silane Arborols $(VII)^1$

  • 김정균;안경미
    • 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.

Application of Microwave Activation Techniques to the N-Alkenyl Protection of Lactams

  • Kim, Ki-Won;Ahn, Hee-Sook;Lee, Ho-Joon;Song, Suk-Jin;Kim, Chung-Gi;Kwon, Tae-Woo
    • 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.

Synthesis of Dendritic Carbosilanes by the Use of Hyperbranched Polymers (Hyperbranched Polymer를 이용한 나뭇가지꼴 카보실란 거대분자의 합성)

  • Kim, Chung Kyun;Kang, Sung Kyung;Park, Eun Mi
    • 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.

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