• 제목/요약/키워드: Asymmetric cyclopropanation

검색결과 4건 처리시간 0.017초

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

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.

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.