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Volumn 126, Issue 28, 2004, Pages 8744-8754

Palladium(0)-catalyzed synthesis of medium-sized heterocycles by using bromoallenes as an allyl dication equivalent

Author keywords

[No Author keywords available]

Indexed keywords

ALCOHOLS; BROMINE COMPOUNDS; CARBON; CATALYSIS; NITROGEN; OXYGEN; SYNTHESIS (CHEMICAL);

EID: 3242672213     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja048693x     Document Type: Article
Times cited : (108)

References (105)
  • 70
    • 3242729802 scopus 로고    scopus 로고
    • note
    • The bromoallenes 13b-d were synthesized according to the reported procedure.9 For synthesis of the bromoallene 13a, see the Supporting Information.
  • 71
    • 0028069277 scopus 로고
    • N-Boc sulfonamides, a useful nitrogen nucleophile in the Mitsunobu reaction, can be readily prepared by the reaction of sulfonamides with di-(tert-butyl) dicarbonate catalyzed by 4-(dimethylamino)pyridine: Neustadt, B. R. Tetrahedron Lett. 1994, 35, 379-380.
    • (1994) Tetrahedron Lett. , vol.35 , pp. 379-380
    • Neustadt, B.R.1
  • 72
    • 3242660348 scopus 로고    scopus 로고
    • note
    • Structure of 24b was confirmed by NOE analysis. Irradiation of the signal of 6-H in 1,4-oxazepine 24b led to NOE enhancement of the signal of 5-H and 1′-H (12.3% for 5-H and 7.2% for 1′-H). (Diagram presented)
  • 73
    • 3242703593 scopus 로고    scopus 로고
    • note
    • For synthesis of bromoallenes 15e and 17e, see the Supporting Information.
  • 74
    • 3242691894 scopus 로고    scopus 로고
    • note
    • The cis-configuration of the eight-membered ring 26 was determined by NOE analysis. For example, in the case of 1,5-oxazocine 26b, NOE was observed between [6-H and 7-H (9.6%)] and [7-H and 1′-H (5.2%)]. (Diagram presented)
  • 75
    • 3242720891 scopus 로고    scopus 로고
    • note
    • The (S,aR)-bromoallenes 28 and 29 were synthesized by the identical procedure shown in Scheme 4 from known allenes.9 For details, see the Supporting Information.
  • 76
    • 3242722668 scopus 로고    scopus 로고
    • note
    • Structure of 32 was confirmed by NOE analysis as shown below. (Diagram presented)
  • 87
    • 3242655876 scopus 로고    scopus 로고
    • note
    • Exposure of the minor product 57 to the cyclization conditions led to complete recovery of 57.
  • 88
    • 3242720890 scopus 로고    scopus 로고
    • note
    • Structure of 64 was confirmed by NOE analysis as shown below. (Diagram presented)
  • 89
    • 3242697375 scopus 로고    scopus 로고
    • note
    • Although formation of benzo-annulated eight-membered ring proceeded in good yields (Table 5, entries 3 and 6), reaction of bromoallene 90 under the same reaction conditions afforded dimethoxylated product 91. Therefore, it is apparent that a substitution which effectively assists the cyclization is essential for the eight-membered ring formation containing one heteroatom. (Diagram presented)
  • 90
    • 3242687436 scopus 로고    scopus 로고
    • note
    • The trans-configuration of 67 was determined by NOE analysis as shown below. (Diagram presented)
  • 96
    • 3242737008 scopus 로고    scopus 로고
    • note
    • 2 gave the 2-vinylpiperidine 93 in 51% yield along with a trace amount of 59 (ca. 1% yield). From this result, the alternative mechanism through the terminal allene 92 cannot be the major reaction pathway. (Diagram presented)
  • 97
    • 0023805222 scopus 로고
    • A palladium(II) catalyst induces nucleophilic reaction onto allenes, see: (a) Prasad, J. S.; Liebeskind, L. S. Tetrahedron Lett. 1988, 29, 4257-4260.
    • (1988) Tetrahedron Lett. , vol.29 , pp. 4257-4260
    • Prasad, J.S.1    Liebeskind, L.S.2
  • 99
    • 0030741861 scopus 로고    scopus 로고
    • Hiemstra reported that the cyclization of allenic lactams takes place at the central carbon atom of allene: (c) Karstens, W. F. J.; Rutjes, F. P. J. T.; Hiemstra, H. Tetrahedron Lett. 1997, 38, 6275-6278.
    • (1997) Tetrahedron Lett. , vol.38 , pp. 6275-6278
    • Karstens, W.F.J.1    Rutjes, F.P.J.T.2    Hiemstra, H.3
  • 101
    • 0032560834 scopus 로고    scopus 로고
    • 2-Vinylpiperidines were synthesized from amino allenes in the presence of a catalytic amount of a palladium complex under weakly acidic conditions: (e) Meguro, M.; Yamamoto, Y. Tetrahedron Lett. 1998, 39, 5421-5424.
    • (1998) Tetrahedron Lett. , vol.39 , pp. 5421-5424
    • Meguro, M.1    Yamamoto, Y.2
  • 102
    • 3242700027 scopus 로고    scopus 로고
    • note
    • 4.12a
  • 104
    • 3242695571 scopus 로고    scopus 로고
    • note
    • For synthesis of the bromoallene 83 bearing two oxygen nucleophiles, see the Supporting Information.
  • 105
    • 3242710766 scopus 로고    scopus 로고
    • note
    • The stereochemistry of the bicyclic product 87 was confirmed by NOE experiment and COSY analysis. (Diagram presented)


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.