Synthesis and<sup>1</sup><i>H</i>NMR structural analysis of 11-aryl/heteroarylnaphtha[2,1-<i>b</i>]furans: X-ray crystal structure of 11-(4′-pyridyl)naphtho[2,1 -<i>b</i>]furan
作者:Sabir H Mashraqui、Mamta B Patil、Yogesh Sangvikar、Mohamed Ashraf、Hitesh D Mistry、Elise Trân Huu Dâub、Auke Meetsma
DOI:10.1002/jhet.5570420530
日期:2005.7
aryl/heteroaryl groups and the naphthofuran plane to be in the range of 70–60° in 8-10, a single X-ray crystal structural analysis of 11-(4′-pyridyl)naphtho[2,1-b]furan 10 indicated (φ) of 64.36°. In view of significant deviations from the orthogonal oreintation, the absence of any significant anisotropic shielding in 8-11 is not entirely unexpected.
为了研究C-11芳基/杂芳基的构象取向,已经描述了联芳基类型系统的合成,即11-芳基/杂芳基萘[2,1- b ]呋喃8-11。8-11的合成是通过两步序列完成的,包括用适当的卤代酮2-4对2-萘酚进行O-烷基化,然后用甲磺酸环化所得的萘氧基-酮5-7。8-11的结构基于详细的2D NMR光谱分析。这些化合物中的H8不受显着的各向异性高场屏蔽作用的影响。H8在分子9-11中相对于8的略高场化学位移与C17和C8位置的电子密度相关。虽然分子模型表明C11芳基/杂芳基基团与萘呋喃平面之间的二面角(φ)在8-10之间在70–60°的范围内,但对11-(4'-吡啶基)萘并[2,1- b ]呋喃10的(φ)为64.36°。考虑到与正交定律的显着偏差,在8-11中不存在任何显着的各向异性屏蔽并不是完全意外的。