• 제목/요약/키워드: Cyclopropanation

검색결과 9건 처리시간 0.029초

1,2-Ferrocenedilazaphosphinines 3:A New Class fo Planar Chiral Ligands for Cu-Catalyzed Cyclopropanation

  • Paek, Seung-Hwan;Co, Thanh Thien;Lee, Dong-Ho;Park, Yu-Chul;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
    • /
    • 제23권12호
    • /
    • pp.1702-1708
    • /
    • 2002
  • The synthesis and catalytic application of a new class of a new class of planar chiral ferrocenes, 1,2-ferrocenediylazaphosphinines (1 and 2) are described. They are powerful ligands for the copper(I)-catalyzed asymmetric cyclopropanation of a range of alkenes with diazo esters to exhibit an exceptionally high degree of diastereoselectivity(~100% de) in favor of trans isomers, regardless the structure of the olefins and the diazo compounds. Comparative studies between 1 and 2 reveal that the former works better in terms of diastereocontrol. In contrast, however, enantioselectivity is low with both 1 and 2 as a whole although, in certain cases with a proper combination of the olefin and the diazo ester, high optical yields (up to 100% ee) can be achieved. Other reaction parameters such as the reaction temperature and the structure of the ligand do exhibit some influence, although infinitestimal, on both chemical and optical yields.

페로센을 이용한 비대칭 유기합성용 금속 촉매의 개발 (Development of Ferrocene-Containing Metal Catalysts for Asymmetric Synthesis)

  • 오영희;최미진
    • 공업화학
    • /
    • 제10권5호
    • /
    • pp.804-807
    • /
    • 1999
  • 페로센 카르복시알데히드와 1,2-diaminocyclohexane을 2:1로 반응시켜 키랄 리간드 L(L=N,N'-cyclohexane bis(ferrocenylmethylene)amine)을 합성하고 이를 구리와 반응시켜 새로운 구리 착물을 합성하였다. 이 착물들을 확인하고 비대칭 유기 합성반응에 촉매로 사용하였다. 구리(II) 착물들은 스티렌과 에틸디아조아세테이트와의 시클로프로판화 반응에서 촉매작용을 하지 않았으나 구리(I)화합물, Cu(I)LOTf (OTf=trifluoromethanesulfonate)는 시클로프로판 생성물 trans:cis의 비율에 있어 80:20 이상의 높은 regioselectivity를 보였다.

  • PDF

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
    • /
    • 제23권5호
    • /
    • pp.721-726
    • /
    • 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.

삼각고리를 포함한 Norbornane 골격을 가진 화합물의 합성 및 물성에 관한 연구 (A Study on the Synthesis and Property of Norbornane Type Carbocyclic Compounds that Include 3-membered Fused Ring System)

  • 오창호;한정식;박대인;류중현;조준현
    • 한국추진공학회:학술대회논문집
    • /
    • 한국추진공학회 2006년도 제26회 춘계학술대회논문집
    • /
    • pp.202-205
    • /
    • 2006
  • 현재 우주항공 분야에서 액체연료의 다양한 물성과 비추력이 요구됨으로 이를 만족시킬 수 있는 새로운 형태 및 조성의 액체연료를 개발할 필요성이 요구된다. 일부 국가에선 액체 연료로, 다중고리를 포함한 탄소고리 화합물을 연구, 개발하여 사용하고 있다. 이에 우리는 여러 개의 고리가 포함된 화합물들을 합성하고자 연구를 진행하였고, 그 중 Norbornane 골격에 삼각고리를 증가시킨 화합물들을 합성하였고, 이들 화합물의 발열량 및 밀도를 측정하였다.

  • PDF

Synthesis and Antiviral Activity of Novel C-Methyl Branched Cyclopropyl Nucleosides

  • Kwak, Eun-Yee;Hong, Joon-Hee;Park, Young-Jak;Choi, Bo-Gil
    • Archives of Pharmacal Research
    • /
    • 제26권9호
    • /
    • pp.679-685
    • /
    • 2003
  • A series of novel cyclopropyl nucleosides was synthesized using the highly stereoselective Simmons-Smith reaction starting from 1,2:5,6-di-Ο-isopropylidene-D-mannitol. The structural assignments of these nucleosides were determined by NMR studies and X-ray crystallography. All the synthesized nucleosides were assayed against several viruses.

Transition Metal-Catalyzed and -Promoted Reactions via Carbene and Vinylidene Complexes Generated from Alkynes

  • Ohe, Kouichi
    • Bulletin of the Korean Chemical Society
    • /
    • 제28권12호
    • /
    • pp.2153-2161
    • /
    • 2007
  • The transition metal-induced in situ generation of carbene complexes from alkynes having a carbonyl or imino group as a nucleophilic functionality has been investigated. These reactive carbenoid species are generated with high atom efficiency through a 6-endo-dig cyclization mode based on the electrocyclization of vinylidene complexes or a 5-exo-dig cyclization mode in π-alkyne complexes, and have been found to serve as versatile intermediates in catalytic carbene transfer reactions. Highlighted and reviewed in this account are the generation and preparation of pyranylidene, furylcarbene, pyrrolylcarbene, and vinylcarbene complexes and their application to [3,3]sigmatropic rearrangement of acylcyclopropylvinylidenes, catalytic cyclopropanation reactions, [2,3]sigmatropic rearrangement or condensation reactions via ylides, ring-opening and substitution reactions with heteroaromatic compounds, and catalytic isomerization of oligoynes.

Stereoselective Palladium Catalyzed Cyclizations of Enediyne Compounds

  • 오창호;임철윤;정형훈;정승현
    • Bulletin of the Korean Chemical Society
    • /
    • 제20권6호
    • /
    • pp.643-647
    • /
    • 1999
  • Hydropalladium carboxylates, formed from π-allylpalladium chloride dimer plus carboxylic acids, have been shown to catalyze cyclization of structurally diverse enediynes to form the corresponding six- or five-membered rings depending upon the reaction conditions. Some enediynes having an Oxygen linker in an appropriate position under the similar condition yielded the corresponding cyclopropanation products in highly stereoselective manner. A study using deuterated formic acid has proven that the alkylpalladium intermediates formed in our conditions were reduced by the pendant formate ligand. The dienediyne 10 yielded only the tricyclic product 12 in 67% yield, although it was expected to frrm the cyclic product 11. All these cyclizations seemed to occur via the corresponding alkylpalladium intermediates I. which could proceed to the corresponding cyclic products depending on the reaction conditions and the substrates. The study using ceuterated formic acid could provide an important information to understand the present cyclization mechanism. Overall the present study could play an important role in developing new synthetic methodologies for constructing complex polycyclic compounds.

고에너지 고밀도 고리탄화수소 화합물의 구조에 따른 물성 연구 (Study on Properties of High Energetic and High Dense Cyclic Hydrocarbons by the Structure)

  • 조준현;권태수;정덕진;오창호;박대인;한정식
    • 한국추진공학회:학술대회논문집
    • /
    • 한국추진공학회 2008년도 제31회 추계학술대회논문집
    • /
    • pp.463-466
    • /
    • 2008
  • 액체 추진기관을 적용하는 무기체계는 용도가 점차 증가되는 추세에 있으며, 운용목적 및 환경에 따라 다양한 물성을 가진 액체연료의 수요도 많아지고 있다. norbornane 또는 dicyclopentane 구조를 포함한 고리탄화수소 화합물은 고밀도 고에너지 특성을 바탕으로 다양한 유도무기체계에 적용되고 있으며, 현재도 많은 분야에서 연구 대상이 되고 있다. 본 연구에서는 분자물질의 설계 및 이를 대상으로 합성한 다양한 고리형 탄화수소화합물의 물성을 분석하여 그 구조에 따라 밀도와 발열량등 이화학 특성이 어떤 경향을 나타내는지 알아보았다.

  • PDF