2001 Fiscal Year Final Research Report Summary
New, Rational Synthetic Transformations Based on the Oxidation Potentials as Universal Reactivity Indices
| Project/Area Number |
11305064
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
有機工業化学
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
YOSHIDA Jun-ichi Kyoto University, Graduate School of Engineering, Professor, 工学研究科, 教授 (30127170)
|
|---|
| Project Period (FY) |
1999 – 2001
|
| Keywords | oxidation potential / electro-auxiliary / orbital interaction / organometallic reaction |
|---|
| Research Abstract |
We have investigated new synthetic transformations based on rational design and prediction of the reactivity of reactants using the oxidation potentials as universal reactivity indices. We have developed a new and highly effective electro-auxiliary ; 2-pyridylsilyl group, which can be also used for removable intramolecular ligand for metal-mediated and catalyzed reactions.
The oxidation potential of the α-2-pyridylsilyl-substituted sulfide is considerably lower than that of the non-substituted one, and the effect of 2-pyridylsilyl group can be explained by the intramolecular participation of the pyridyl group to the sulfur-derived radical cation spesies, which are generated by single electron oxidation of the starting substrate. This participation effect is also supported by the fact that 2-pyridylsilyl group possesses stronger effect than ordinary organosilyl group to decrease the oxidation potentials of divalent organosulfur compounds.
The results above suggest that the basicity of 2-pyridylsilyl group is stronger than that of pyridine because of the existence of the interaction of the n-orbital of the pyridyl nitrogen and the σ-orbital of the C-Si bond. Therefore, 2-pyridylsilyl group is expected to serve as a powerful intramolecular ligand in metal-mediated and catalyzed reactions. Inside, we have succeeded in developing various organometallic-mediate synthetic reactions, including the hydrosilylation, the Heck-type reaction, the Stille-type reaction, the carbomagnesiation, and the deprotonation of silylmethyl groups.
|
