2003 Fiscal Year Final Research Report Summary
Nitrogen-pyramidal Amides. Generality and Application.
| Project/Area Number |
14370719
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Chemical pharmacy
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
OHAWADA Tomohiko The University of Tokyo, Graduate School of Pharmaceutical Sciences, Professor, 大学院・薬学系研究科, 教授 (20177025)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
UCHIYAMA Masanobu The University of Tokyo, Graduate School of Pharmaceutical Sciences, Lecturer, 大学院・薬学系研究科, 講師 (00271916)
|
|---|
| Project Period (FY) |
2002 – 2003
|
| Keywords | amide / nitrogen pyramidalized amide / twisted amide / 7-azabicyclo[2.2.1]hepatane / solution structure / density-functional theory |
|---|
| Research Abstract |
We showed that amides of bicyclic 7-azabicyclo[2.2.1]heptane are intrinsically nitrogen-pyramidal. Single-crystal X-ray diffraction structures of some relevant bicyclic amides, including the prototype N-benzoyl-7-azabicyclo[2.2.1]heptane, exhibited nitrogen-pyramidalization in the solid state. We evaluated the rotational barriers about the amide bonds of various N-benzoyl-7-azabicyclo[2.2.1]heptanes in solution. The observed reduction of the rotational barriers of the bicyclic amides, as compared with those of the monocyclic pyrrolidine amides, is consistent with a nitrogen-pyramidal structure of 7-azabicyclo[2.2.1]heptane amides in solution. A good correlation was found between the magnitudes of the rotational barrier of N-benzoyl 7-azabicyclo[2.2.1]heptanes bearing para-substituents on the benzoyl group and the Hammett's δ_p^+ constants. Calculations with the density-functional theory reproduced the nitrogen-pyramidal structures of these bicyclic amides as energy minima. The calculated magnitudes of electron delocalization from the nitrogen non--bonding nH orbital to the carbonyl π^* orbital of the amide group evaluated by application of the bond model theory, correlated well with the rotational barriers of a variety of amides, including amides of 7-azabicyclo[2.2.1]heptane. Non-planarity of the amide nitrogen of 7-azabicyclo[2.2.1]heptanes would be derived from nitrogen-pyramidalization due to the CNC angle strain, and twisting of the amide bond due to the allylic strain.
|
Research Products
(6 results)
-
-
-
-
[Publications] Uchiyama, M., Miyoshi, T., Kajihara, Y., Sakamoto, T., Otani, Y., Ohwada, T., Kondo, Y.: "Generation of Functionalized Asymmetric Benzynes Using TMP Zincates. Effects of Ligands on Selectivity and Reactivity of Zincates"J.Am.Chem.Soc. 124. 8514-8515 (2002)
Description
「研究成果報告書概要(欧文)」より
-
-
