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Volumn 8, Issue 6, 1997, Pages 841-844

Silica gel supported bis-cinchona alkaloid: A highly efficient chiral ligand for heterogeneous asymmetric dihydroxylation of olefins

Author keywords

[No Author keywords available]

Indexed keywords

ALKENE DERIVATIVE; CINCHONA ALKALOID; LIGAND; SILICA GEL;

EID: 0030949856     PISSN: 09574166     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0957-4166(97)00074-8     Document Type: Article
Times cited : (65)

References (29)
  • 1
    • 0000067960 scopus 로고
    • Catalytic asymmetric dihydroxylation
    • Ojima, I., Ed.; VCH publishers: New York
    • Review: (a) Johnson, R. A. and Sharpless, K. B. Catalytic Asymmetric Dihydroxylation. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH publishers: New York, 1993; pp 221-212.
    • (1993) Catalytic Asymmetric Synthesis , pp. 221-1212
    • Johnson, R.A.1    Sharpless, K.B.2
  • 21
    • 0030272832 scopus 로고    scopus 로고
    • Recently, Lohray et al. reported the immobilization of 3-dihydroquininyl-6-quininylpyridazine on silica gel support. This silica gel supported alkaloid exhibited comparable reactivity with that of its homogeneous analogue, however much more inferior enantioselectivity; Lohray, B. B.; Nandanan, E.; Bhushan, V. Tetrahedron: Asymmetry 1996, 7, 2805.
    • (1996) Tetrahedron: Asymmetry , vol.7 , pp. 2805
    • Lohray, B.B.1    Nandanan, E.2    Bhushan, V.3
  • 25
    • 0343449684 scopus 로고    scopus 로고
    • note
    • Immobilization of monomer 1 on silica gel: LiChrosorb SI 60 (Merck, 5 μm, 5.25 g) was treated with 23 ml of (3-mercaptopropyl)trimethoxysilane in 22 ml of anhydrous 1:1 pyridine/toluene. The slurry was heated at 90°C for 24 hours. After filtration the solid was washed (toluene, acetone, diethyl ether, pentane) and dried under vacuum for 1 hr, resulting in 6.05 g of a derivatized silica containing 3.82% S, corresponding to 1.19 mmol of S per g of derivatized silica. This derivatized silica 2 (5.98 g) was suspended in chloroform and refluxed with 1,4-bis(9-O-quininyl)phthalazine (2.90 g) and α,α'-azoisobutyronitrile (AIBN, 165 mg), as radical initiator, for 48 hours. Again, after filtration, the solid was exhaustively washed with methanol until the 1,4-bis(9-O-quininyl)phthalazine in excess was completely removed and dried under vacuum.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.