Using Incoming Nucleophile Primary Hydrogen−Deuterium Kinetic Isotope Effects To Model the SN2 Transition State
| العنوان: | Using Incoming Nucleophile Primary Hydrogen−Deuterium Kinetic Isotope Effects To Model the SN2 Transition State |
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| المؤلفون: | and Yao-ren Fang, Terry Koerner, Kenneth Charles Westaway |
| المصدر: | Journal of the American Chemical Society. 122:7342-7350 |
| بيانات النشر: | American Chemical Society (ACS), 2000. |
| سنة النشر: | 2000 |
| مصطلحات موضوعية: | Substituent, Leaving group, chemistry.chemical_element, General Chemistry, Photochemistry, Biochemistry, Chloride, Catalysis, Transition state, chemistry.chemical_compound, Colloid and Surface Chemistry, Nucleophile, chemistry, Kinetic isotope effect, medicine, Chlorine, SN2 reaction, medicine.drug |
| الوصف: | The primary hydrogen−deuterium incoming nucleophile KIEs for the SN2 reactions between para-substituted benzyl chlorides and borohydride ion in DMSO at 30.000 ± 0.002 °C are small (≤1.14) and insensitive to a change in substituent at the α-carbon. The small Hammett ρ (0.51) and ρr (−0.52) values found when the para substituent on the benzene ring of the substrate is altered indicate there is very little charge on the α-carbon in the transition state. The large, constant secondary α-deuterium KIEs of 1.089 ± 0.002 and the large chlorine leaving group KIEs of 1.0076, 1.0074, and 1.0078 found for the p-methyl-, the p-hydrogen-, and the p-chlorobenzyl chloride reactions suggest that the transition states for these reactions are unsymmetric with short H−Cα and long B−Η and Cα−Cl bonds. The decrease in the chlorine leaving group KIE from 1.0076 ± 0.0003 for the p-methylbenzyl chloride reaction to 1.0036 ± 0.0003 for the p-nitrobenzyl chloride reaction indicates the Cα−Cl bond shortens markedly when a strongly e... |
| تدمد: | 1520-5126 0002-7863 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::051e0de119b92c4ab4ee64847d4008db https://doi.org/10.1021/ja000441i |
| رقم الأكسشن: | edsair.doi...........051e0de119b92c4ab4ee64847d4008db |
| قاعدة البيانات: | OpenAIRE |
Find this issue from the American Chemical Society | تدمد: | 15205126 00027863 |
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