• 제목/요약/키워드: Chiral ligand

검색결과 51건 처리시간 0.022초

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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    • 제26권9호
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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.

  • https://doi.org/10.5012/bkcs.2005.26.9.1359 인용 PDF KSCI

Chiral C2-Symmetric α-and ω-Diimines with Bulky Substituents at Nitrogen: Synthesis and Catalytic Properties of Some Copper Complexes

  • Park, Dong-Kyu;Ryu, Eun-Sook;Paek, Seung-Hwan;Shim, Sang-Chul;Cho, Chan-Sik;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
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    • 제23권5호
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    • pp.721-726
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    • 2002

  • Two new C2-symmetric chiral $\alpha-$ and w-Diimines incorporating bulky ferrocenylethylamine and their copper(I)complexes have been synthesized and characterized by analytical and various spectroscopic techniques. The catalytic activities of these complexes have been tested in the asymmetric cyclopropanation of a series of olefins with some diazoacetates to achieve varying degree of dia- and enantio-selectivities depending on the nature of the ligand, the substrates, and the reagents. Some mechanistic implication has been made with regard to the interactions among all these chemical species.

  • https://doi.org/10.5012/bkcs.2002.23.5.721 인용 PDF KSCI

Cinchona 알칼로이드를 키랄 리간드로 이용한 비대칭 Reformatsky 반응 (Enantioselective Reformatsky Reaction Using Cinchona Alkaloids as Chiral Ligands)

  • 박두한;최호진;이상기
    • 대한화학회지
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    • 제47권6호
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    • pp.597-600
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    • 2003

  • Cinchona 알칼로이드(1-4)들을 비대칭 Reformatsky 반응에 키랄 리간드로 사용하였다. 알데히드, 리간드, Reformatsky 시약의 적가 순서에 따라 반응의 수율이 달라지며, Reformatsky 시약과 알데히드, 리간드와의 비율도 수율에 크게 영향을 주었다.

  • https://doi.org/10.5012/jkcs.2003.47.6.597 인용 PDF KSCI KPUBS HTML