Evidence for Silicon-Directed Acid-Catalysed Ring Opening of a β,γ-Epoxy Silane: Reaction of 1,1-Dimethyl-1-silacyclohex-3-ene Oxide With p-Nitrobenzoic Acid
摘要:
在氯仿中,β,γ-环氧硅烷 (4) 与对硝基苯甲酸发生特异性开环反应,生成两种羟基酯 (14) 和 (15)。其机理涉及特定区域的开环,产生 β-硅稳定的硒离子 (18),该离子被对硝基苯甲酸反离子捕获。(14)的溶液构象证明在环的 C- Si 键轨道和 C-OCOC6H4NO2 反键轨道之间存在 σC- Si -σ* C-O 相互作用。在丙酮中,(4)与对硝基苯甲酸的反应采用不同的途径,由于溶剂对硅的侵蚀而产生无环产物。
Evidence for Silicon-Directed Acid-Catalysed Ring Opening of a β,γ-Epoxy Silane: Reaction of 1,1-Dimethyl-1-silacyclohex-3-ene Oxide With p-Nitrobenzoic Acid
摘要:
在氯仿中,β,γ-环氧硅烷 (4) 与对硝基苯甲酸发生特异性开环反应,生成两种羟基酯 (14) 和 (15)。其机理涉及特定区域的开环,产生 β-硅稳定的硒离子 (18),该离子被对硝基苯甲酸反离子捕获。(14)的溶液构象证明在环的 C- Si 键轨道和 C-OCOC6H4NO2 反键轨道之间存在 σC- Si -σ* C-O 相互作用。在丙酮中,(4)与对硝基苯甲酸的反应采用不同的途径,由于溶剂对硅的侵蚀而产生无环产物。
Acetolysis of 4,4-disubstituted 4-silacyclohexyl tosylates: effect of remote silicon substitution on organic reactivity
作者:Stephen S. Washburne、Ram R. Chawla
DOI:10.1016/s0022-328x(00)98112-9
日期:1977.6
and phenyl-methyl-substituted 4-silacyclohexyl tosylates (IcId) were compared with isosteric 4,4-disubstituted cyclohexyl tosylates. The rates of acetolysis of the silatosylates were three to five times greater than those of the carbocyclic analogs. With the exception of Ia, which largely fragmented to di-4-pentenyltetramethyldisiloxane, the acetolysis products of compounds I were acetates and olefins