• 제목/요약/키워드: Alkenes

검색결과 88건 처리시간 0.027초

Facile Formation of Unexpected [m,6,n]-tricyclic Spiranes via Intramolecular [3+2] Cyclization of Platinum-bound Pyrylium with Alkenes

  • Oh, Chang-Ho;Tak, Sang-Yong;Lee, Ji-Ho;Piao, Lanhua
    • Bulletin of the Korean Chemical Society
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    • 제32권spc8호
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    • pp.2978-2980
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    • 2011
  • Enynals bearing an olefinic pendant were successfully cyclized via Huisgen-type [3+2] cycloaddition to the tetracyclic Pt-carbene complexes which would undergo insertion into a C-H bond of the ${\beta}$-position to afford the fused cyclopropane intermediates. Their tandem rearrangement afforded diverse types of spiranes depending on the tethered alkenes of the enynals.

Influence of Maleic Anhydride Grafted onto Polyethylene on Pyrolysis Behaviors

  • Chung, Yu Yeon;Choi, Sung-Seen
    • Elastomers and Composites
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    • 제51권3호
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    • pp.233-239
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    • 2016
  • Polyethylene (PE) and maleic anhydride-grafted PE (PE-g-MAH) were pyrolyzed, and their pyrolysis products were analyzed using gas chromatography/mass spectrometry (GC/MS) to investigate the influence of MAH grafted onto PE on pyrolysis behaviors. Major pyrolysis products of PE and PE-g-MAH were n-alkanes, 1-alkenes, ${\alpha},{\omega}$-alkadienes, and aromatic compounds. 1-Alkenes were more formed than n-alkanes, ${\alpha},{\omega}$-alkadienes, and aromatic compounds. Butadiene was more produced from PE than PE-g-MAH, whereas toluene and ethyl benzene were more generated from PE-g-MAH than PE. Difference in the pyrolysis behaviors between PE and PE-g-MAH were explained by initial decomposition of MAH moiety.

개선된 QSPR 방법에 의한 알켄의 생성열 (Improved QSPR Prediction of Heats of Formation of Alkenes)

  • Duchowicz, P.;Castro, E.A.
    • 대한화학회지
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    • 제44권6호
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    • pp.501-506
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    • 2000
  • 탄화수소의 생성엔탈피를 예측하는 이전의 선형방정식들을 일반화하였다. QSPR 분석에서 사용된 분자를 표현하는 기본적인 인자는 원자와 화학결합이다. 이러한 선택은 이 방법을 매우 간단하게 하며 비용을 줄일 수 있게 한다. 19개의 알켄에 대한 예측치는 실험오차 정도의 편차를 준다. 이 방법의 몇몇 가능한 확장에 대해 지적하였다.

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The Rapid and Efficient Synthesis of Bromohydrins from Olefins under HBr/H2O2 System by Visible Light Induced

  • Tang, Rui-Ren;Gong, Nian-Hua
    • Bulletin of the Korean Chemical Society
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    • 제30권8호
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    • pp.1832-1834
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    • 2009
  • A simple and safe method has been presented for conversion of olefins into bromohydrins using hydrogen bromide and hydrogen peroxide as bromide source by visible light induced within a very short time to get high yield bromohydrins along with a little mount dibromo-product. In this paper, cyclohexene is firstly carried out as the model substrate and investigated the bromination under HBr/$H_2O_2$ system using 150 W incandescent light irradiated in C$Cl_4$ within short time to get good yield of 2-bromocyclohexanol along with a little mount of 1,2-dibromocyclohexane; then, a series of alkenes are brominated to corresponding bromohydrins using the same protocol.

BNBTS More than Brominating Agent: Green and One-pot Route for the C-N Bond Formation in Water from Alkenes

  • Kazemi, Foad;Kakroudi, Mazaher Abdollahi
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.500-504
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    • 2013
  • In this paper, in addition to introducing efficient method for bromohydrin and bromoether preparation, simple, green and efficient method to C-N bond formation from alkene and N,N'-Dibromo-N,N'-1,2-ethanediyl-bis(p-toluenesulfonamide) [BNBTS] in water was investigated. The reaction between alkenes, ${\beta}$-cyclodexterin, and BNBTS took place in water afterward, by making media basic; it will give the corresponding valuable building blocks in good yields (45-79%).

Remarkable Productselectivity in Photocycloaddition of Diarl Compounds and in Photosensitized Oxidation of Alkenes within Supramolecular System

  • Chen-Ho Tung;Li-Zhu Wu;Zhen-Yu Yuan;Jing-Qu Guan;Hong-Wei Wang;Li-Ping Zhang
    • Journal of Photoscience
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    • 제6권3호
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    • pp.85-90
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    • 1999
  • Supramolecular photochemistry is concerned with systems where non-covalent interactions become significant or dominate in determining the chemistry of guest/host systems. The photocycloaddition of diaryl compounds and the photosensitized oxidation of alkenes included in zeolites, low-density polyethylene films and Nafion membranes is the subject of this report.

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Isopinocampheylhaloborane-Methyl Sulfide as Hydroborating and Stereoselective Reducing Agent

  • 차진순;민수진;김종미;권오운;김은주
    • Bulletin of the Korean Chemical Society
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    • 제16권1호
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    • pp.37-42
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    • 1995
  • Reactions of alkenes and alkynes with the recently discovered isopinocampheylhaloborane-methyl sulfide (IpcBHX·SMe2, X=Cl, Br, I) were investigated in detail in order to establish their usefulness as hydroborating agents. The reagents readily hydroborated alkenes at 50 ℃ and alkynes at 25 ℃ with excellent regioselectivity in placing the boron atom exclusively at the less hindered carbon atom. Especially, the selectivity achieved by the iodo derivative reaches essentially 100%. In addition to that, IpcBHX·SMe2 was applied to the reduction of cyclic ketones to examine its stereoselectivity. The halogen substituent in these reagents plays an important role in the stereoselective reduction. The stereoselectivity increased dramatically with increasing steric size of the substituent. Finally, the iodo derivative achieved highly stereoselective reduction, such selectivity being comparable to that previously achieved with trialkylborohydrides.