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Volumn 75, Issue 5, 2010, Pages 1733-1739

Catalyst-controlled regioselective suzuki couplings at both positions of dihaloimidazoles, dihalooxazoles, and dihalothiazoles

Author keywords

[No Author keywords available]

Indexed keywords

CHEMICAL EQUATIONS; CYCLOPROPYL; HIGH SELECTIVITY; PALLADIUM CATALYST; RAPID CONSTRUCTION; REGIO-SELECTIVE; SUZUKI COUPLINGS;

EID: 77949309795     PISSN: 00223263     EISSN: 15206904     Source Type: Journal    
DOI: 10.1021/jo100148x     Document Type: Article
Times cited : (48)

References (31)
  • 10
    • 0033524876 scopus 로고    scopus 로고
    • For an earlier methodology involving selective iodination of oxazoles at C4 via lithiation see: Vedejs, E.; Luchetta, L. M. J. Org. Chem. 1999, 64, 1011.
    • For an earlier methodology involving selective iodination of oxazoles at C4 via lithiation see: Vedejs, E.; Luchetta, L. M. J. Org. Chem. 1999, 64, 1011.
  • 14
    • 33646456316 scopus 로고    scopus 로고
    • Selective Suzuki couplings of 2,3-dibromo-5-formylpyrroles and dibromopyridines have been reported: (a) Handy, S. T.; Sabatini, J. J. Org. Lett. 2006, 8, 1537-1539.
    • Selective Suzuki couplings of 2,3-dibromo-5-formylpyrroles and dibromopyridines have been reported: (a) Handy, S. T.; Sabatini, J. J. Org. Lett. 2006, 8, 1537-1539.
  • 17
    • 68949113487 scopus 로고    scopus 로고
    • 11 and 2,4-dibromothiazole is C2: Martin, T.; Laguerre, C.; Hoarau, C.; Marsais, F. Org. Lett. 2009, 11, 3690-3693.
    • 11 and 2,4-dibromothiazole is C2: Martin, T.; Laguerre, C.; Hoarau, C.; Marsais, F. Org. Lett. 2009, 11, 3690-3693.
  • 18
    • 0043032712 scopus 로고    scopus 로고
    • The preferred site of SNAr on 2,4-dibromothiazoles with thiols is C2: Nicolaou, K. C.; Sasmal, P. K.; Rassias, G.; Reddy, M. V.; Altmann, K.-H.; Wartmann, M.; O'Brate, A.; Giannakakou, P. Angew. Chem., Int. Ed. 2003, 42, 3515-3520.
    • The preferred site of SNAr on 2,4-dibromothiazoles with thiols is C2: Nicolaou, K. C.; Sasmal, P. K.; Rassias, G.; Reddy, M. V.; Altmann, K.-H.; Wartmann, M.; O'Brate, A.; Giannakakou, P. Angew. Chem., Int. Ed. 2003, 42, 3515-3520.
  • 19
    • 33645454183 scopus 로고    scopus 로고
    • 1H NMR shifts of the parent non-halogenated compound incorrectly predicts reaction at C2 of 2,4-diiodooxazole and 2,5-dibromo-1-methylimidazole: Handy, S. T.; Zhang, Y. Chem. Commun. 2006, 299-301.
    • 1H NMR shifts of the parent non-halogenated compound incorrectly predicts reaction at C2 of 2,4-diiodooxazole and 2,5-dibromo-1-methylimidazole: Handy, S. T.; Zhang, Y. Chem. Commun. 2006, 299-301.
  • 20
    • 77949302144 scopus 로고    scopus 로고
    • All LC-MS ratios were estimated by using the LC area percentage at either 210 or 254 nm.
    • All LC-MS ratios were estimated by using the LC area percentage at either 210 or 254 nm.
  • 21
    • 77949303912 scopus 로고    scopus 로고
    • In the absence of added base, phenylzinc bromide could be coupled with 2,4-diiodoxazole with use of ligand 2 and under otherwise identical conditions, giving similar selectivities to those obtained with phenylboronic acid
    • In the absence of added base, phenylzinc bromide could be coupled with 2,4-diiodoxazole with use of ligand 2 and under otherwise identical conditions, giving similar selectivities to those obtained with phenylboronic acid.
  • 22
    • 77949290600 scopus 로고    scopus 로고
    • 2 to form, the bis compound.
    • 2 to form, the bis compound.
  • 23
    • 77949293003 scopus 로고    scopus 로고
    • 4. It was discovered in subsequent experiments that phosphine-free palladium gave comparable results to palladium with 6.
    • 4. It was discovered in subsequent experiments that phosphine-free palladium gave comparable results to palladium with 6.
  • 24
    • 77949290933 scopus 로고    scopus 로고
    • The identity of 5-iodo-1-methyl-2-phenylimidazole was determined solely by LC-MS and showed a very different retention time than its isomer 2-iodo-1-methyl-5-phenylimidazole
    • The identity of 5-iodo-1-methyl-2-phenylimidazole was determined solely by LC-MS and showed a very different retention time than its isomer 2-iodo-1-methyl-5-phenylimidazole. This product readily decomposed upon attempted isolation.
    • This product readily decomposed upon attempted isolation
  • 25
    • 0035801641 scopus 로고    scopus 로고
    • A highly selective Negishi coupling at C2 of 2,4-dibromothiazole has been reported as part of a total synthesis: Bach, T.; Heuser, S. Angew. Chem., Int. Ed. 2001, 40, 3184-3185.
    • A highly selective Negishi coupling at C2 of 2,4-dibromothiazole has been reported as part of a total synthesis: Bach, T.; Heuser, S. Angew. Chem., Int. Ed. 2001, 40, 3184-3185.
  • 28
    • 77949295319 scopus 로고    scopus 로고
    • 1H NMR resonance of 5-bromo-2-phenylthiazole did not match that reported in the literature, we compared it to an authentic commercial sample, which matched our cross-coupling product perfectly.
    • 1H NMR resonance of 5-bromo-2-phenylthiazole did not match that reported in the literature, we compared it to an authentic commercial sample, which matched our cross-coupling product perfectly.
  • 29
    • 77949311292 scopus 로고    scopus 로고
    • We hypothesize that catalyst formation may be slow or problematic with these two ligands and 6, allowing phosphine-free palladium to affect the majority of the oxidative addition at C5.
    • We hypothesize that catalyst formation may be slow or problematic with these two ligands and 6, allowing phosphine-free palladium to affect the majority of the oxidative addition at C5.
  • 30
    • 77949303241 scopus 로고    scopus 로고
    • 3P, rather than as a bidentate phosphine.
    • 3P, rather than as a bidentate phosphine.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.