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Volumn 71, Issue 5, 2006, Pages 1969-1976

Rhodium-catalyzed direct C-H addition of 3,4-dihydroquinazolines to alkenes and their use in the total synthesis of vasicoline

Author keywords

[No Author keywords available]

Indexed keywords

HETEROCYCLE DEHYDROGENATION; INTRAMOLECULAR COUPLINGS; QUINAZOLINES; VASICOLINE;

EID: 33644638345     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo052345b     Document Type: Article
Times cited : (65)

References (92)
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    • note
    • The unusual profile observed for the conversion of 2 to 3 cannot be fully explained at this time.
  • 38
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    • note
    • The product of transfer hydrogenation, 2,2-dimethylbutane, was also detected at levels commensurate with 4 formation.
  • 43
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    • note
    • The role of the acid additive in accelerating catalysis has not yet been ascertained.
  • 44
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    • note
    • 4f
  • 45
    • 33644641055 scopus 로고    scopus 로고
    • note
    • 4f compared to coupling reactions of less substituted olefins.
  • 46
    • 0032560025 scopus 로고    scopus 로고
    • An elegant, but less convergent method for preparing N3-substituted DHQs involves selective alkylation of o-aminobenzylamine, using 9-BBN as a protecting and directing group: Bar-Haim, G.; Kol, M. Tetrahedron Lett. 1998, 39, 2643.
    • (1998) Tetrahedron Lett. , vol.39 , pp. 2643
    • Bar-Haim, G.1    Kol, M.2
  • 47
    • 37049049568 scopus 로고
    • The sole report of nucleophilic alkylation of 2 (with iodomethane) claims exclusive N3-selectivity. We were unable to reproduce this result: Armarego, W. L. J. Chem. Soc. 1961, 2697.
    • (1961) J. Chem. Soc. , pp. 2697
    • Armarego, W.L.1
  • 48
    • 33644643856 scopus 로고    scopus 로고
    • note
    • Isomeric mixtures were separated by chromatography.
  • 49
    • 84989059352 scopus 로고
    • - (bent). For a previous synthesis of phosphonium dihalohydrogenate salts with neat hydrogen halides at low temperatures see: Kohle, R.; Kuchen, W.; Peters, W. Z. Anorg. Allg. Chem. 1987, 551, 179.
    • (1987) Z. Anorg. Allg. Chem. , vol.551 , pp. 179
    • Kohle, R.1    Kuchen, W.2    Peters, W.3
  • 57
    • 0009394701 scopus 로고
    • Vasicolinone has also been twice synthesized in tandem with rutaecarpine, another structurally homologous quinazolinone alkaloid: (a) Kaneko, C.; Chiba, T.; Kasai, K.; Miwa, C. Heterocycles 1985, 23, 1385.
    • (1985) Heterocycles , vol.23 , pp. 1385
    • Kaneko, C.1    Chiba, T.2    Kasai, K.3    Miwa, C.4
  • 68
    • 33644655218 scopus 로고    scopus 로고
    • note
    • We also considered altering our synthetic route by exchanging the dimethylamino group for an N-protected amino group. These efforts led to lengthy reaction sequences.
  • 69
    • 33644651560 scopus 로고    scopus 로고
    • note
    • This two-step sequence was preferred to direct reduction of o-chlorocinnamic acid because common procedures for carboxylic acid reduction gave competitive conjugate reduction.
  • 70
    • 33644652683 scopus 로고    scopus 로고
    • note
    • 3 method is more amenable to use on large scale.
  • 72
    • 33644653251 scopus 로고    scopus 로고
    • Personal communication
    • Cy-[3.3.1]-Phoban was prepared in moderate yield by alkylation of H-[3.3.1]-Phoban with BuLi/CyBr: (a) Meyer, W. H. Personal communication.
    • Meyer, W.H.1
  • 74
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    • note
    • 2 with 1,5-cyclooctadiene (see ref 42).
  • 76
    • 33644651249 scopus 로고    scopus 로고
    • note
    • A synthesis of the -Br analogue of 23 was undertaken starting from 2-bromocinnamic acid. The method used to prepare 23 proved ineffective in this effort; the Rh-catalyzed cyclization step produced an uncharacterized mixture of decomposition products.
  • 81
    • 0035909622 scopus 로고    scopus 로고
    • 2. Unfortunately, these reaction conditions did not function for 23, probably due to its base sensitivity: Huang, X. H.; Buchwald, S. L. Org. Lett. 2001, 3, 3417.
    • (2001) Org. Lett. , vol.3 , pp. 3417
    • Huang, X.H.1    Buchwald, S.L.2
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    • note
    • 3 or Eschweiler-Clarke conditions were used.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.