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Volumn 122, Issue 7, 2000, Pages 1343-1351

Mechanistic study of the ring-enlargement reaction of (3-oxa-2- silacyclopentyl)methyl radicals into 4-oxa-3-silacyclohexyl radicals. Evidence for a pentavalent silicon-bridging radical transition state in 1,2- rearrangement reactions of β-silyl radicals

Author keywords

[No Author keywords available]

Indexed keywords

DEUTERIUM; RADICAL; SILICON; SILICON DERIVATIVE;

EID: 0034003660     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja993239s     Document Type: Article
Times cited : (34)

References (55)
  • 24
    • 0342826138 scopus 로고
    • A gas-phase 1,2-shift of a trimethylsilyl group from silicon to carbon radical is observed at 600 °C; however, no 1,2-shift occurs when the same radical is generated in solution: Sakurai, H.; Kishida, T.; Hosomi, A.; Kumada, M. J. Organomet. Chem. 1967, 8, 65-68.
    • (1967) J. Organomet. Chem. , vol.8 , pp. 65-68
    • Sakurai, H.1    Kishida, T.2    Hosomi, A.3    Kumada, M.4
  • 31
    • 0032724353 scopus 로고    scopus 로고
    • Radical reactions of 1 and 2 have been described in a communication: Sugimoto, I.; Shuto, S.; Matsuda, A. Synlett. 1999, 1766-1768.
    • (1999) Synlett. , pp. 1766-1768
    • Sugimoto, I.1    Shuto, S.2    Matsuda, A.3
  • 33
    • 0343696661 scopus 로고    scopus 로고
    • note
    • When the methyl protons and the methyne proton adjacent to the silicon were irradiated, NOEs as shown in Figure 1 were observed.
  • 34
    • 0342826136 scopus 로고    scopus 로고
    • note
    • Although the stereochemistries of 9a and 9b were confirmed by the NOE data as shown in Figure 2, no NOE was observed when the silyl methyl protons of 10a or 10b were irradiated. Therefore, the configurations at the silicon of 10a and 10b were confirmed based on chemical shifts of the methyl groups attached to the silicon of the compounds having benzo-[f]-2-oxa-3-silabicyclo[3.3.0]octane or benzo[g]-2-oxa-3-silabicyclo[4.3.0]-nonane structure synthesized in this study: the signals of the exo-SiMe protons in 1b, 1d, 9b, and 10b (0.43-0.57 ppm) were observed at lower fields compared with those of the endo-SiMe protons in 1a, 1c, 9a, and 10a (-0.02-0.18 ppm) presumably due to deshielding by the benzene ring condensed with the 2-oxa-3-silabicyclo[3.3.0]octane or 2-oxa-3-silabicyclo-[4.3.0]nonane ring (see Figure 2).
  • 35
    • 0002452792 scopus 로고
    • It is known that inversion of configuration at a silicon atom in organo-silicon compounds readily occurs via pseudorotation: Holmes, R. R. Chem. Rev. 1990, 90, 17-31.
    • (1990) Chem. Rev. , vol.90 , pp. 17-31
    • Holmes, R.R.1
  • 36
    • 0342826137 scopus 로고    scopus 로고
    • note
    • 2O-hexane, a mixture of 9a and 9b (ratio, ca. 1:1) was obtained.
  • 40
    • 0342391409 scopus 로고    scopus 로고
    • note
    • 2, -1232.0125841 hartrees; D′, -1232.0226381 hartrees; ia, -1043.848567 hartrees; iva, -1043.857157 hartrees; ib, -1043.842205 hartrees; ivb, -1043.857857 hartrees (1 hartree = 627.51 kcal/mol).


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.