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Volumn 13, Issue 16, 2011, Pages 4268-4271

Rapid assembly of quinolizidines via consecutive nucleophilic cyclizations onto activated amides

Author keywords

[No Author keywords available]

Indexed keywords

AMIDE; PROTON; QUINOLIZIDINE DERIVATIVE;

EID: 80051694624     PISSN: 15237060     EISSN: 15237052     Source Type: Journal    
DOI: 10.1021/ol201616k     Document Type: Article
Times cited : (47)

References (27)
  • 21
    • 33846312573 scopus 로고    scopus 로고
    • The first example of double intramolecular nucleophilic trapping of activated amides was reported by our group (ref 11). The single closest related example is the activation of a carbamate and subsequent nucleophilic trapping. See
    • The first example of double intramolecular nucleophilic trapping of activated amides was reported by our group (ref 11). The single closest related example is the activation of a carbamate and subsequent nucleophilic trapping. See: Magnus, P.; Gazzard, L.; Hobson, L.; Payne, A. H.; Rainey, T. J.; Westlund, N.; Lynch, V. Tetrahedron 2002, 58, 3423
    • (2002) Tetrahedron , vol.58 , pp. 3423
    • Magnus, P.1    Gazzard, L.2    Hobson, L.3    Payne, A.H.4    Rainey, T.J.5    Westlund, N.6    Lynch, V.7
  • 22
    • 0038292651 scopus 로고
    • When the nucleophile is an indole or an aryle, the reaction is rather called a Bischler-Napieralski cyclization
    • When the nucleophile is an indole or an aryle, the reaction is rather called a Bischler-Napieralski cyclization: Bischler, A.; Napieralski, B. Chem. Ber. 1893, 26, 903
    • (1893) Chem. Ber. , vol.26 , pp. 903
    • Bischler, A.1    Napieralski, B.2
  • 23
    • 29144475769 scopus 로고    scopus 로고
    • Since thorough degassing of the reaction mixture to remove oxygen prior to addition of triflic anhydride did not prevent the formation of pyridinium 13 the oxidation is believed to occur via deprotonation of eniminium 12 and oxidation of the resulting 1,2-dihydropyridine by hydride transfer to reduce iminium species in solution and to generate pyridinium 13. For an example of oxidation of 1,2-dihydropyridine to pyridinium ion via hydride transfer, see
    • Since thorough degassing of the reaction mixture to remove oxygen prior to addition of triflic anhydride did not prevent the formation of pyridinium 13 the oxidation is believed to occur via deprotonation of eniminium 12 and oxidation of the resulting 1,2-dihydropyridine by hydride transfer to reduce iminium species in solution and to generate pyridinium 13. For an example of oxidation of 1,2-dihydropyridine to pyridinium ion via hydride transfer, see: Cattoe, X.; Bourissoua, D.; Bertrand, G. Tetrahedron 2006, 47, 531
    • (2006) Tetrahedron , vol.47 , pp. 531
    • Cattoe, X.1    Bourissoua, D.2    Bertrand, G.3
  • 24
    • 0037241494 scopus 로고    scopus 로고
    • We observed the following decreasing order of nucleophilicity: allylstannane > allylsilane with non-substituted nucleophilic carbon (cf. 1a) > allylsilane with substituted nucleophilic carbon (cf. 9) > vinylsilane. This order is in accord with Mayr's calculated nucleophilicity of carbon nucleophiles. See
    • We observed the following decreasing order of nucleophilicity: allylstannane > allylsilane with non-substituted nucleophilic carbon (cf. 1a) > allylsilane with substituted nucleophilic carbon (cf. 9) > vinylsilane. This order is in accord with Mayr's calculated nucleophilicity of carbon nucleophiles. See: Mayr, H.; Kempf, B.; Ofial, A. R. Acc. Chem. Res. 2003, 36, 66
    • (2003) Acc. Chem. Res. , vol.36 , pp. 66
    • Mayr, H.1    Kempf, B.2    Ofial, A.R.3
  • 25
    • 58049202981 scopus 로고    scopus 로고
    • We do not have a clear explanation to why, in this case, we observed a competitive deprotonation to 16. We could presume that the vinyl group induces a conformation in which the indicated proton in 26 (Scheme 3) is acidified due to a better alignment with the p orbital of the carbocation. For another recent example of competition between desilylation and deprotonation, see
    • We do not have a clear explanation to why, in this case, we observed a competitive deprotonation to 16. We could presume that the vinyl group induces a conformation in which the indicated proton in 26 (Scheme 3) is acidified due to a better alignment with the p orbital of the carbocation. For another recent example of competition between desilylation and deprotonation, see: Lee, M. H.; Nieto-Oberhuber, C.; Shair, D. M. J. Am. Chem. Soc. 2008, 130, 16864
    • (2008) J. Am. Chem. Soc. , vol.130 , pp. 16864
    • Lee, M.H.1    Nieto-Oberhuber, C.2    Shair, D.M.3


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.