Control of Electron Transfer Reactions on the Basis of Dynamic Intramolecular Coordination

基于动态分子内配位的电子转移反应控制

• 批准号: 13640532
• 负责人: SUGA Seiji
• 金额: $ 2.18万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640532/
• 关键词: electron Transfer; organosilicon compound; cation rdical; electrolysis; pyridylethyl group; Dynamic Intramolecular Coordination

The present work stems from our earlier observations that the introduction of carbonyl, alkoxy, and pyridyl groups decreases the oxidation potential of tetraalkylstannanes. There is no indication of the coordination in the neutral molecule by the spectroscopy. Therefore, the decrease of the oxidation potential seems to be attributed to the dynamic intramolecular coordination to tin in the cation radical intermediates. Such coordination stabilizes the cation radical which in turn favors the electron transfer and also controls the selectivity of the bond cleavage. Pyridyl group has been found to be especially effective among the examined.Thus new class of electroauxiliary, [2-(2-pyridyl)etyl]dimethylsilyl group has been developed. Introduction of 2-(2-pyridyl)ethyl group on silicon atom of α-silylethers and sulfides gives rise to decrease of their oxidation potentials. Studies based on NMR spectra, ab initio molecular orbital calculations, and solvent effect of oxidation have suggested that the decrease of the oxidation potentials is attributed to the 'dynamic intramolecular coordination' of pyridyl group to silicon. The reactivity of this new electroauxiliary has been compared with those of trimethylsilyl group and tributylstannyl group by competition experiments. The present study indicates the feasibility of fine tuning of the reactivity of electroauxiliaries using dynamic intramolecular coordination.

目前的工作源于我们早期的观察，羰基，烷氧基和吡啶基基团的引入降低了四烷基锡烷的氧化电位。通过光谱学没有指示中性分子中的配位。因此，氧化电位的降低似乎归因于在阳离子自由基中间体中与锡的动态分子内配位。这种配位稳定了阳离子自由基，这反过来有利于电子转移，也控制了键断裂的选择性。其中吡啶基是最有效的电辅助基团，因此发展了一类新的电辅助基团，[2-（2-吡啶基）乙基]二甲基硅基。在α-硅醚和硫醚的硅原子上引入2-（2-吡啶基）乙基，使它们的氧化电位降低。基于NMR光谱、从头计算分子轨道计算和氧化的溶剂效应的研究表明，氧化电位的降低归因于吡啶基与硅的“动态分子内配位”。通过竞争实验比较了这种新型电助剂与三甲基硅基和三丁基锡基的反应活性。本研究表明了利用动态分子内配位微调电助剂反应性的可行性。

项目成果

Suga, S., Watanabe, M., Yoshida, J.: "Electroauxiliary-Assisted Sequential Introduction of Two Carbon Nucleophiles on the Same α-Carbon of Nitrogen : Application to the Synthesis of Spiro Compounds"Journal of the American Chemical Society. 124. 14824-1482

Suga, S.、Watanabe, M.、Yoshida, J.：“在氮的同一 α-碳上电辅助连续引入两个碳亲核试剂：在螺化合物合成中的应用”美国化学会杂志 124。 .14824-1482

Suga, S. ; Suzuki, S. ; Yoshida, J.: "Reduction of a Cation Pool A New Approach to Radical Mediated C-C Bond Formation"Journal of the American Chemical Society. 124. 30-31 (2002)

须贺，S.；

Suga, S., Okajima, M., Yoshida, J.: "Reaction of Electrogenerated "Iminium Cation Pool" with Organometallic Reagents. Direct Oxidative α-Alkylation and -Arylation of Amine Derivatives"Tetrahedron Letters. 42. 2173-2176 (2001)

Suga, S.、Okajima, M.、Yoshida, J.：“电化学“亚胺阳离子池”与有机金属试剂的反应。胺衍生物的直接氧化 α-烷基化和芳基化”四面体快报 42。2173-2176（2001 年） ）

吉田潤一, 菅 誠治: "カチオンフロー法を用いたシリアルコンビナトリアル合成"有機合成化学協会誌. 60. 482-483 (2002)

Junichi Yoshida、Seiji Suga：“使用阳离子流法的串行组合合成”有机合成化学学会杂志 60. 482-483 (2002)。

Yoshida, J., Suga, S: "Basic Concepts of"Cation Pool"and "Cation Flow"Methods and Their Applications in Conventional and Combinatorial Organic Synthesis"Chemistry-A European Journal. 8. 2650-2658 (2002)

Yoshida, J.，Suga, S：““阳离子池”和“阳离子流”方法的基本概念及其在常规和组合有机合成中的应用”化学-欧洲期刊。