標題: | [2.2.2.2](2,7)-1-Bromonaphthalenophane from a Desymmetrized Building Block Bearing Electrophilic and Masked Nucleophilic Functionalities |
作者: | Cai, Guangke Chatterjee, Shreyam Hisaki, Ichiro Tobe, Yoshito 應用化學系 Department of Applied Chemistry |
關鍵字: | cyclophanes;stereochemistry;conformation analysis;cyclization;nucleophilic substitution |
公開日期: | 1-三月-2019 |
摘要: | In search of 2,7-ethylene-bridged naphthalenophanes with desymmetrized naphthalene cores as inherently chiral cyclophanes, nucleophilic substitution of 1-bromo-7-(bromomethyl)-2-[(trimethylsilyl)methyl]naphthalene, a desymmetrized building block bearing an electrophilic group (CH2Br) and a masked nucleophilic functionality (CH2TMS) which can be activated by fluoride anion, was examined. As a result, in contrast to the case of parent naphthalenophanes wherein the smallest [2.2]naphthalenophane was obtained as the major product, only [2.2.2.2](2,7)-1-bromonaphthalenophane was obtained albeit in low yields, whereas the corresponding [2.2]- or [2.2.2]naphthalenophanes were not obtained. Though the [2.2.2.2]-1-bromonaphthalenophane can adopt four idealized geometries of different symmetry, among which three are inherently chiral, theoretical calculations predict that three conformers have almost equal energy and may equilibrate in solution. The X-ray crystallographic study shows that it adopts a C-2 conformation with anti,anti,anti orientation of the C-Br bonds at least as a major component in crystal. |
URI: | http://dx.doi.org/10.1002/hlca.201800242 http://hdl.handle.net/11536/151618 |
ISSN: | 0018-019X |
DOI: | 10.1002/hlca.201800242 |
期刊: | HELVETICA CHIMICA ACTA |
Volume: | 102 |
Issue: | 3 |
起始頁: | 0 |
結束頁: | 0 |
顯示於類別: | 期刊論文 |