• Title/Summary/Keyword: Allylic alkylation

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Synthesis of an Intermediate for Carbaprostacyclin: Stereoselective Synthesis of 1-Alkoxy-3-benzenesulfonyl-3-cyano-4-ethenyl cyclopentane (카바프로스타싸이클린 중간체의 합성 : 1-Alkoxy-3-benzenesulfonyl-3-cyano-4-ethenyl cyclopentane의 입체선택적 합성)

  • 서영거;정재경;구본암;최영기;조윤상
    • YAKHAK HOEJI
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    • v.39 no.1
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    • pp.41-47
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    • 1995
  • An efficient and stereoselective synthetic route to the trisubstituted hydroxy cyclopentane as an useful synthetic intermediate for carbaprostacyclin is described. Pd(0)-mediated intramolecular alkylation of allylic carbonate has been employed as a key reaction.

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Catalytic Asymmetric Allylic Alkylation with A Novel P-S Bidentate Ligand

  • Gang, Ja Hyo;Yu, Seong Hun;Kim, Ju In;Jo, Hyeong Geun
    • Bulletin of the Korean Chemical Society
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    • v.16 no.5
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    • pp.439-443
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    • 1995
  • Both enantiomers of (S)-(-)-2-(diphenylphosphino)-2'-mercapto-1,1'-binaphthyl and their derivatives were obtained by synthesis from racemic 2,2'-dihydroxy-1,1'-binaphthyl and subsequent resolution. The utilities of these ligands were investigated briefly. And among these, S-methyl derivative 15 has proved to be an effective ligand for Pd-catalyzed allylic alkylation.

Chiral [Iminophosphoranyl]ferrocenes: Synthesis, Coordination Chemistry, and Catalytic Application

  • Co, Thanh Thien;Shim, Sang-Chul;Cho, Chan-Sik;Kim, Dong-Uk;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
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    • v.26 no.9
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    • pp.1359-1365
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    • 2005
  • A series of new chiral [iminophosphoranyl]ferrocenes, {${\eta}^5-C_5H_4-(PPh_2=N-2,6-R_2-C_6H_3)$}Fe{${\eta}^5-C_5H_3-1-PPh^2-2-CH(Me)NMe_2$} (1: R = Me, $^iPr$), {${\eta}^5{-C_5H_4-(PPh_2=N-2,6-R_2}^1-C_6H_3)$}Fe{${\eta}^5-C_5H_3-1-(PPh_2=N-2,6-R_2-C_6H_3)-2-CH(Me)R_2$} (2: $R^1\;=\;Me,\;^iPr;\;R^2\;=\;NMe_2$, OMe), and $({\eta}^5-C_5H_5)Fe${${\eta}^5-C_5H_4-1-PR_2-2-CH(Me)N=PPh_3$} (3:R = Ph, $C_6H_{11}$) have been prepared from the reaction of [1,1'-diphenylphosphino-2-(N,N-dimethylamino) ethyl]ferrocene with arylazides (1 & 2) and the reaction of phosphine dichlorides ($R_3PCl_{2}$) with [1,1'-diphenylphosphino-2-aminoethyl]ferrocene (3), respectively. They form palladium complexes of the type $[Pd(C_3H_5)(L)]BF_4$ (4-6: L = 1-3), where the ligand (L) adopts an ${\eta}^2-N,N\;(2)\;or\;{\eta}^2$-P,N (3) as expected. In the case of 1, a potential terdentate, an ${\eta}^2$-P,N mode is realized with the exclusion of the –=NAr group from the coordination sphere. Complexes 4-6 were employed as catalysts for allylic alkylation of 1,3-diphenylallyl acetate leading to an almost stoichiometric product yield with modest enantiomeric excess (up to 74% ee). Rh(I)-complexes incorporating 1-3 were also prepared in situ for allylic alkylation of cinnamyl acetate as a probe for both regio- and enantioselectivities of the reaction. The reaction exhibited high regiocontrol in favor of a linear achiral isomer regardless of the ligand employed.