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Volumn 62, Issue 2-3, 2006, Pages 264-284

Formamides derived from N-methyl amino acids serve as new chiral organocatalysts in the enantioselective reduction of aromatic ketimines with trichlorosilane

Author keywords

Asymmetric reduction; Enantiopure amines; Hydrosilylation; Imines; Lewis bases; Organocatalysis

Indexed keywords

AMIDE; AMINO ACID DERIVATIVE; AROMATIC COMPOUND; IMINE; SILANE DERIVATIVE; TRICHLOROSILANE; UNCLASSIFIED DRUG;

EID: 28944440055     PISSN: 00404020     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tet.2005.08.117     Document Type: Article
Times cited : (103)

References (98)
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    • For recent reports on catalytic hydrogenation (with Ti, Ir, Rh, and Ru), see Refs. 1b-d and the following: (a) D. Xiao, and X. Zhang Angew. Chem., Int. Ed. 40 2001 3425
    • (2001) Angew. Chem., Int. Ed. , vol.40 , pp. 3425
    • Xiao, D.1    Zhang, X.2
  • 16
    • 6444241533 scopus 로고    scopus 로고
    • For Rh-catalyzed hydrogenation of enamides, see the following: (j) X.-P. Hu, and Z. Zheng Org. Lett. 6 2004 3585
    • (2004) Org. Lett. , vol.6 , pp. 3585
    • Hu, X.-P.1    Zheng, Z.2
  • 47
    • 0041878778 scopus 로고    scopus 로고
    • Activation of other trichlorosilanes with Lewis basic organocatalysts has now been well established. For a review on chiral phosphoramides, see: (a) S.E. Denmark, and J. Fu Chem. Rev. 103 2003 2763
    • (2003) Chem. Rev. , vol.103 , pp. 2763
    • Denmark, S.E.1    Fu, J.2
  • 61
    • 28944444872 scopus 로고    scopus 로고
    • note
    • To obtain 14 in high yield, it is crucial to add NaH (in small portions) to a mixture of BOC-valine 13 and MeI. If the deprotonation of 13 is carried out prior to the addition of MeI, the methylation becomes inefficient.
  • 75
    • 28944437375 scopus 로고    scopus 로고
    • note
    • 3 was <5%, and ∼10% in MeCN.
  • 78
    • 0032522196 scopus 로고    scopus 로고
    • Chloroform has been shown to be the solvent that most strongly stabilizes the arene-arene interactions: G.A. Breault, C.A. Hunter, and P.C. Mayers J. Am. Chem. Soc. 120 1998 3402
    • (1998) J. Am. Chem. Soc. , vol.120 , pp. 3402
    • Breault, G.A.1    Hunter, C.A.2    Mayers, P.C.3
  • 79
    • 28944435993 scopus 로고    scopus 로고
    • note
    • While imines 1a-d,f,g,k all exists as pure (E)-isomers, NMR spectra of 1e,h indicate 11:1 and 14:1 (E/Z)-mixtures, respectively.
  • 80
    • 0032922728 scopus 로고    scopus 로고
    • This strategy is commonly used in design of chiral selectors in chiral chromatography: W.H. Pirkle, and M.E. Koscho J. Chromatogr. A 840 1999 151
    • (1999) J. Chromatogr. a , vol.840 , pp. 151
    • Pirkle, W.H.1    Koscho, M.E.2
  • 81
    • 28944454223 scopus 로고    scopus 로고
    • note
    • 3SiH shows two peaks at 21.69 and 21.76 ppm.
  • 82
    • 28944448577 scopus 로고    scopus 로고
    • note
    • 9
  • 83
    • 28944443864 scopus 로고    scopus 로고
    • note
    • Preliminary experiments show striking conformational differences in the X-ray structures of several of these derivatives, which may lend further credence to this hypothesis. Details will be published in due course.
  • 84
    • 28944436744 scopus 로고    scopus 로고
    • note
    • For the oxidative removal of the N-(p-methoxyphenyl) group to obtain the corresponding primary amine, see Ref. 2a.
  • 98
    • 28944434265 scopus 로고    scopus 로고
    • note
    • S retention times were swapped for 2a,b,d,g by mistake.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.