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Volumn , Issue 1, 2009, Pages 89-91

Mild stereoselective hydrohalogenation leading to (Z)-halopropenamides at room temperature

Author keywords

(Z) halopropenamides; (Z) halopropenoic esters; Hydrohalogenation; Tert butyl halide; Zinc halide

Indexed keywords


EID: 62349093375     PISSN: 09365214     EISSN: 14372096     Source Type: Journal    
DOI: 10.1055/s-0028-1087489     Document Type: Article
Times cited : (12)

References (36)
  • 9
    • 0001044764 scopus 로고
    • For coupling reaction with organozirconocenes, see: i
    • For coupling reaction with organozirconocenes, see: (i) Crombie, L.; Hobbs, A. J. W.; Horsham, M. A. Tetrahedron Lett. 1987, 28, 4875.
    • (1987) Tetrahedron Lett , vol.28 , pp. 4875
    • Crombie, L.1    Hobbs, A.J.W.2    Horsham, M.A.3
  • 19
    • 84981795044 scopus 로고    scopus 로고
    • For the preparation of (E)-3-bromopropenamides via the reaction of 3-aminopropynal with HBr followed by rearrangement, see: (a) Neuenschwander, M.; Hafner, K. Angew. Chem., Int. Ed. Engl. 1968, 7, 460.
    • For the preparation of (E)-3-bromopropenamides via the reaction of 3-aminopropynal with HBr followed by rearrangement, see: (a) Neuenschwander, M.; Hafner, K. Angew. Chem., Int. Ed. Engl. 1968, 7, 460.
  • 22
    • 0346099779 scopus 로고    scopus 로고
    • For the synthesis of (E)- or (Z)-iodopropenamides via peptide coupling reaction between the corresponding (E)- or (Z)-iodopropenoic acids and an amine, see refs. 1d, 3, 4. For aminolysis of acyl chlorides prepared from 3-bromo- or 3-iodopropenoic acids leading to a mixture of Z- and E-isomers, see: (d) Wilson, R. M.; Commons, T. J. J. Org. Chem. 1975, 40, 2891.
    • For the synthesis of (E)- or (Z)-iodopropenamides via peptide coupling reaction between the corresponding (E)- or (Z)-iodopropenoic acids and an amine, see refs. 1d, 3, 4. For aminolysis of acyl chlorides prepared from 3-bromo- or 3-iodopropenoic acids leading to a mixture of Z- and E-isomers, see: (d) Wilson, R. M.; Commons, T. J. J. Org. Chem. 1975, 40, 2891.
  • 28
    • 62349104821 scopus 로고    scopus 로고
    • The reactions were generally performed at 90°C over 22-48 h. At 70°C lower yields were obtained (see ref. 8b).
    • The reactions were generally performed at 90°C over 22-48 h. At 70°C lower yields were obtained (see ref. 8b).
  • 30
    • 62349141707 scopus 로고    scopus 로고
    • Using only 2 equivalents of tert-butyl iodide led to lower yields
    • Using only 2 equivalents of tert-butyl iodide led to lower yields.
  • 32
    • 62349108441 scopus 로고    scopus 로고
    • This might be correlated to the relative basicity of amides and sulfoxides
    • This might be correlated to the relative basicity of amides and sulfoxides.
  • 33
    • 62349117851 scopus 로고    scopus 로고
    • Z)-N,N-Diallyl-3-iodoacrylamide(2d, Typical Procedure To a solution of N,N-diallyl-3-propynamide (50 mg, 0.335 mmol) in CH2Cl2 (1.7 mL) were added t-BuI (200 μL, 1.67 mmol, 3 equiv) and ZnI2 (214 mg, 0.67 mmol, 2 equiv) at r.t. After 18 h, H2O (5 mL) was added, and the reaction mixture was extracted twice with CH2Cl2. The organic layers were dried over MgSO4, filtered, and concentrated under reduce pressure. Flash chromatography on SiO2 (100% pentane then 100% Et2O) afforded 2d (81 mg, 0.293 mmol, 87, 1H NMR (300 MHz, δ, 3.85 (br d, J, 5.1 Hz, 2 H, 4.05 (br d, J, 5.9 Hz, 2 H, 5.11-5.28 (m, 4 H, 5.68-5.89 (m, 2 H, 6.85 (d, J, 8.8 Hz, 1 H, 7.10 (d, J, 8.8 Hz, 1 H, 13C NMR (75 MHz, δ, 47.4 (CH2, 49.9 CH2, 87.6, CHI, 117.9
    • +: 278.0036; found: 278.0035.
  • 35
    • 62349128716 scopus 로고    scopus 로고
    • Owing to complexation of the product to zinc salts, the olefinic protons are more deshielded in the crude reaction mixture - before aqueous treatment - than in the pure isolated product 2d (δ = 7.0 ppm and 7.4 ppm with a coupling constant equal to 9.1 Hz: 6.85 ppm and 7.10 ppm with a coupling constant equal to 8.8 Hz, respectively).
    • Owing to complexation of the product to zinc salts, the olefinic protons are more deshielded in the crude reaction mixture - before aqueous treatment - than in the pure isolated product 2d (δ = 7.0 ppm and 7.4 ppm with a coupling constant equal to 9.1 Hz: 6.85 ppm and 7.10 ppm with a coupling constant equal to 8.8 Hz, respectively).
  • 36
    • 62349130249 scopus 로고    scopus 로고
    • Using zinc bromide led to degradation of benzylic and propargylic esters
    • Using zinc bromide led to degradation of benzylic and propargylic esters.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.