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Volumn 72, Issue 17, 2007, Pages 6595-6598

Mechanistic studies of the allylic rearrangements of α-silyloxy allylic silanes to silyloxy vinylic silanes

Author keywords

[No Author keywords available]

Indexed keywords

MOLECULAR STRUCTURE; REACTION KINETICS; STABILIZATION;

EID: 34547960964     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo070634p     Document Type: Article
Times cited : (7)

References (24)
  • 5
    • 34547952433 scopus 로고    scopus 로고
    • 2 and 2-nitropropane. Other solvents such as toluene and propionitrile provided the rearrangement, but other products were also formed.
    • 2 and 2-nitropropane. Other solvents such as toluene and propionitrile provided the rearrangement, but other products were also formed.
  • 6
    • 34547952037 scopus 로고    scopus 로고
    • Analysis of the isolated vinylic silane indicates that the partial chirality transfer occurred with retention of configuration. The analysis consisted of deprotection of the vinylic silane to afford the alcohol S6 and comparing it to the known7 alcohol (R)-S6, using chiral HPLC analysis.7 Chemical Equation Presented
    • 7 (Chemical Equation Presented)
  • 8
    • 34547933472 scopus 로고    scopus 로고
    • Analysis was performed with the use of optical rotations because the allylic silanes could not be resolved by HPLC. Attempts to deprotect allylic silanes were unsuccessful due to a competing Brook rearrangement
    • Analysis was performed with the use of optical rotations because the allylic silanes could not be resolved by HPLC. Attempts to deprotect allylic silanes were unsuccessful due to a competing Brook rearrangement.
  • 9
    • 0001332620 scopus 로고    scopus 로고
    • 2t-Bu group see: Chen, X.; Hortelano, E. R.; Eliel, E. L.; Frye, S. V. J. Am. Chem. Soc. 1992, 114, 1778-1784.
    • 2t-Bu group see: Chen, X.; Hortelano, E. R.; Eliel, E. L.; Frye, S. V. J. Am. Chem. Soc. 1992, 114, 1778-1784.
  • 10
    • 34547929605 scopus 로고    scopus 로고
    • Possible conformations C1-C3 were calculated by using ab initio calculations performed at the HF/6-31G* level, using Macspartan (Wave-function, Irvine, CA). Conformation C1 was the lowest energy conformer by 0.51 kcal/mol relative to C2. Conformer C3 was found to not be an energy minimum. (Chemical Equation Presented)
    • Possible conformations C1-C3 were calculated by using ab initio calculations performed at the HF/6-31G* level, using Macspartan (Wave-function, Irvine, CA). Conformation C1 was the lowest energy conformer by 0.51 kcal/mol relative to C2. Conformer C3 was found to not be an energy minimum. (Chemical Equation Presented)
  • 11
    • 34547941962 scopus 로고    scopus 로고
    • CO is much better in C1 than C2 because the two orbitals are orthogonal to each other in C2.
    • CO is much better in C1 than C2 because the two orbitals are orthogonal to each other in C2.
  • 12
    • 0025305009 scopus 로고    scopus 로고
    • The barrier to rotation of the allyl cation is estimated to be 36-38 kcal/mol: (a) Wiberg, K. B.; Breneman, C. M.; LePage, T. J. J. Am. Chem. Soc. 1990, 112, 61-72.
    • The barrier to rotation of the allyl cation is estimated to be 36-38 kcal/mol: (a) Wiberg, K. B.; Breneman, C. M.; LePage, T. J. J. Am. Chem. Soc. 1990, 112, 61-72.
  • 14
    • 34547943057 scopus 로고    scopus 로고
    • Attempts to influence the rearrangement by varying the size of the silyl substituent were unsuccessful. Utilizing the Me3Si-protected allylic silane led to the deprotected α-hydroxy allylic silane. Utilizing the i-Pr3-Si-protected allylic silane, the rearrangement proceeded at the same rate, within experimental error, as the t-BuMe 2Si-protected allylic silane
    • 2Si-protected allylic silane.
  • 15
    • 34547957401 scopus 로고    scopus 로고
    • The energetic difference between 1-trimethylsilyl-1-trimethylsilyl- oxybutane and 1-trimethylsilyl-3-trimethylsilyloxybutane was calculated using ab initio calculations performed at the HF/6-31G* level. 1-Trimethylsilyl-3-trimethylsilyloxybutane was lower in energy, presumably for steric reasons. (Chemical Equation Presented)
    • The energetic difference between 1-trimethylsilyl-1-trimethylsilyl- oxybutane and 1-trimethylsilyl-3-trimethylsilyloxybutane was calculated using ab initio calculations performed at the HF/6-31G* level. 1-Trimethylsilyl-3-trimethylsilyloxybutane was lower in energy, presumably for steric reasons. (Chemical Equation Presented)
  • 16
    • 34547930106 scopus 로고    scopus 로고
    • 3Si groups, suggesting that this was indeed a steric phenomenon and not an electronic one. (Chemical Equation Presented)
    • 3Si groups, suggesting that this was indeed a steric phenomenon and not an electronic one. (Chemical Equation Presented)
  • 17
    • 34547941240 scopus 로고    scopus 로고
    • 18 Ab initio calculations were performed at the HF/6-31G* level. (Chemical Equation Presented)
    • 18 Ab initio calculations were performed at the HF/6-31G* level. (Chemical Equation Presented)


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.