• Title/Summary/Keyword: ylide

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Synthesis of Oligoquinoline Dendronized Fullerenes for Potential Use in Organic Photovoltaic Devices

  • Kwon, Tae-Woo;Jenekhe, Samson A.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.8
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    • pp.2703-2706
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    • 2012
  • New C60 fullerenes derivatives [G1]-C60 (1) and [G2]-C60 (2) comprising of phenylenevinylene bridges and phenylquinoline peripheral surface groups were synthesized by 1,3-dipolar cycloaddition reaction of fullerene C60 with azomethine ylide in situ generated from [Gx]-CHO dendrons (x = 1 and 2) and sarcosine.

Synthesis of 6-Alkoxy-3-(1-hydroxyalkyl)-5-nitro-4,5,6,7-terahydroindole-4-carboxylates

  • 김호현;구양모;이윤영
    • Bulletin of the Korean Chemical Society
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    • v.20 no.8
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    • pp.929-934
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    • 1999
  • 2-( β-Alkoxyvinyl)-4-(1-hydroxyalkyl)pyrroles (14) were synthesized from 4-acylpyrrole-2-carboxylates (8) by sequential reduction of their acyl and alkoxycarbonyl groups to give 4-(1-hydroxyalkyl)pyrrole-2-carbalde-hydes (13) followed by Wittig reaction of the aldehydes with the ylide of alkoxymethylphosphonium chloride. Diels-Alder reaction of 2-(β-alkoxyvinyl)-4-(1-hydroxyalkyl)pyrroles with trans-methyl β-nitroacrylate gave 6-alkoxy-3-(1-hydroxyalkyl)-5-nitro-4,5,6,7-tetrahydroindole-4-carboxylates (3).

Explorative and Mechanistic Studies of the Photooxygenation of Sulfides

  • Albini, Angelo;Bonesi, Sergio M.
    • Journal of Photoscience
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    • v.10 no.1
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    • pp.1-7
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    • 2003
  • The results of recent work on the dye-sensitized photooxygenation of sulfides is discussed. In the case of dialkyl sulfides, the weakly bonded adduct initially formed with singlet oxygen (the persulfoxide) decays unproductively unless protonation by an acid (an alcohol or a carboxylic acid) facilitates its conversion to the sulfoxide. The effect is proportional to the strength of the acid (eg., less than 0.1 % chloroacetic acid in benzene is sufficient for maximal efficiency) and corresponds to general acid catalysis, suggesting that protonation of the persulfoxide occurs. On the other hand, with sulfides possessing an activated hydrogen in ${\alpha}$ position (eg., benzyl and allyl sulfides), hydrogen transfer becomes an efficient process in aprotic media and yields a S-hydroperoxysulfoniumm ylide, possibly arising from a conformation of the persulfoxide that is different from the one protonated in the presence of acids. Calculations on some substituted sulfides support this hypothesis. This process, which leads to C-S bond fragmentation with formation of an aldehyde, may be viewed as a general method for the preparation of aryl and heteroaryl aldehydes. In this effort, mechanistic studies offered new hints on the structure of the intermediate persulfoxide.

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Synthesis and Biological Test of the Pheromone of the Asian Corn Borer Moth (Ostrina Furnacalis)

  • Kang, Suk-Ku;Goh, Hyun-Gwan;Park, Jung-Min;Hwang, Kyung-Lan;Lee, Jeong-Uhn
    • Bulletin of the Korean Chemical Society
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    • v.6 no.1
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    • pp.15-19
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    • 1985
  • (Z)-12-Tetradecen-1-yl acetate (1), (E)-12-tetradecen-1-yl acetate (2) and tetradecan-1-yl acetate (3), the active components of the sex pheromone of the Asian Corn Borer moth were synthesized by two different methods, one from acetylene and 11-bromo-1-undecanol THP ether by acetylenic route, the other from 12-acetoxy-1-dodecanal and ethylidenetriphenylphosphonium ylide by Wittig route.

A Wittig Route to (Z)-13-Eicosen-10-one, the Pheromone of the Peach Fruit Moth, and Its Biological Activity Test

  • Kang, Suk-Ku;Park, Jung-Min;Yoo, Kyung-Ok;Lee, Jeong-Oon;Goh, Hyun-Gwan
    • Bulletin of the Korean Chemical Society
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    • v.6 no.2
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    • pp.86-90
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    • 1985
  • (Z)-13-Eicosen-10-one, an active component of the sex pheromone of the peach fruit moth was synthesized from 4-oxo-tridecan-1-al and heptylidenetriphenylphosphonium ylide by Wittig reaction. The key intermediate, 4-oxo-tridecan-1-al, was synthesized by three different methods. The biological activity test of the synthetic pheromone as attractant for the male peach fruit moth was tested at several districts in Korea.

A Convergent Synthesis of (Z)-13-Octadecen-1-yl Acetate, the Pheromone Mimic of the Rice Leaf Folder Moth and Its Biological Activity Test

  • Kang Suk-Ku;Moon Byoung-Ho;Lee Jeang-Oon;Goh Hyun-Gwan
    • Bulletin of the Korean Chemical Society
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    • v.6 no.4
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    • pp.228-230
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    • 1985
  • (Z)-13-Octadecen-1-yl acetate, the pheromone mimic of the Rice Leaf Folder Moth, Cnaphalocrosis medinalis, was synthesized from 1,13-tridecanediol in three steps. Monoacetylation of 1,13-tridecanediol followed by PCC oxidation gave 13-acetoxytridecan-1-al. Wittig olefination of the 13-acetoxytridecan-1-al with pentylidenetriphenylphosphonium ylide afforded (Z)-13-octadecen-1-yl acetate, the pheromone mimic of the Rice Leaf Folder.

Kinetics of Hydrogen-Deuterium Exchange of 8-CH Groups in Adenosine 5$^\prime$-Monophosphate and Guanosine 5$^\prime$-Monophosphate by Laser Raman Spectroscopy

  • Kim, Sang-Kyu;Kim, Myung-Soo;Suh, Se-Won
    • Bulletin of the Korean Chemical Society
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    • v.6 no.5
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    • pp.270-272
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    • 1985
  • The rate constants of the hydrogen-deuterium exchange of 8-CH groups in 5'-rAMP and 5'-GMP were measured by laser Raman spectroscopy. The Arrhenius activation energies calculated from the rate constants measured as a function of temperature were similar for both compounds. However, the effects of pD on exchange rate constants were different for the two compounds. Our kinetic data support the exchange reaction mechanism involving an ylide type intermediate.

X-ray and Spectroscopy Studies of Mercury (II) and Silver (I) Complexes of α-Ketostabilized Phosphorus Ylides (α-케토안정화된 일리드화 인의 수은(II) 및 은(I) 착물에 대한 X-선 및 분광학적 연구)

  • Karami, K.;Buyukgungor, O.;Dalvand, H.
    • Journal of the Korean Chemical Society
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    • v.55 no.1
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    • pp.38-45
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    • 2011
  • The complexation behavior of the $\alpha$-ketostabilized phosphorus ylides $Ph_3P$=CHC(O) $C_6H_4-X$ (X=Br, Ph) towards the transition metal ions mercury (II) and Silver (I) was investigated. The mercury(II) complex {$HgX_2$ [Y]} 2 ($Y_1$=4-bromo benzoyl methylene triphenyl phosphorane; X=Cl(1), Br(2), I(3), $Y_2$=4-phenyl benzoyl methylene triphenyl phosphorane; X=Cl(4), Br(5), I(6)) have been prepared from the reaction of $Y_1$ and $Y_2$ with $HgX_2$ (X=Cl, Br, I) respectively. Silver complexes [$Ag(Y_2)_2]$ X(X=$BF_4$(7), OTf(8)) of the $\alpha$-keto-stabilized phosphorus ylides ($Y_2$) were obtained by reacting this ylide with AgX (X=$BF_4$, OTf) in $Me_2CO$. The crystal structure of complexes (1) and (4) was discussed. These reactions led to binuclear complexes C-coordination of ylide and trans-like structure of complexes $[Y_1HgCl_2]_2$. $CHCl_3$ (1) and $[Y_2HgCl_2]_2$ (4) is demonstrated by single crystal X-ray analyses. Not only all of complexes have been studied by IR, $^1H$ and $^{31}P$ NMR spectroscopy, but also complexes 1-3 have been characterized by $^{13}$CNMR.

Synthesis and Reactivity of Dinuclear Ni(II) Azido Complexes Containing Bithienylene or Terthienylene Bridging Ligands

  • Kim, Yong-Joo;Lee, Hyuck-Hee;Zheng, Zhen Nu;Lee, Soon-W.
    • Bulletin of the Korean Chemical Society
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    • v.32 no.9
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    • pp.3239-3244
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    • 2011
  • Dinuclear Ni(II)-thiophene halides, which contain linear bridging thienylenes, trans,trans-[$(PR_3)_2$(X)Ni-Y-Ni(X)$(PR_3)_2$] {X = Cl, Br; $H_2Y$ = 5,5'-dichloro-2,2'-bithiophene ($H_2bth$); $H_2tth$ = 5,5"-dichloro-2,2':5',2''-terthiophene ($H_2tth$)} were prepared by the oxidative addition of dihalobithiophene ($H_2bth$) or dihaloterthiophene ($H_2tth$) to [$Ni(COD)_2$] in the presence of tertiary phosphines. Subsequent reactions of $NaN_3$ with the dinuclear Ni(II)-thiophene chlorides gave the corresponding Ni(II)-azido complexes, trans,trans-[$(PR_3)_2(N_3)$Ni-Y-Ni$(N_3)(PR_3)_2$], whose reactivity toward trimethylsilyl pseudohalides such as trimethylsilyl isothiocyanates and cyanides was investigated. In addition, the reaction of trans-[$BrNi(PEt_3)_2-C_4H_2S-C_4H_2S$-CHO], a thienyl Ni(II) complex containing a terminal aldehyde group, with phosphonium ylide was examined.