Condensed O,N-heterocycles containing tetrahydro-1,4-benzoxazepine and tetrahydroquinoline moieties were prepared by a regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction of a 4-aryl-2-phenyl-1,4-benzoxazepine derivative obtained from flavanone. The relative configuration of products were determined by the correlation of 3JH,H coupling data with the geometry of major conformers accessed by DFT conformational analysis. Separated enantiomers of the products were characterized by HPLC-ECD data, which allowed their configurational assignment on the basis of TDDFT-ECD calculation of the solution conformers. Two compounds showed neuroprotective activities against hydrogen peroxide (H2O2) or β-amyloid25–35 (Aβ25–35)-induced cellular injuries in human neuroblastoma SH-SY5Y cells in the range of those of positive controls.
通过从黄烷酮中获得的4-芳基-2-苯基-1,4-苯并噁唑啉衍生物的区域和对映选择性Knoevenagel-[1,5]-氢移位环化反应,制备了含有四氢-1,4-苯并噁唑啉和四氢喹啉基团的浓缩O,N-杂环化合物。通过将3JHH偶合数据与DFT构象分析所访问的主要构象的几何形状相关联,确定了产物的相对构型。通过HPLC-ECD数据表征产物的分离对映体,基于溶液构象的TDDFT-ECD计算确定其构型。两种化合物在人类神经母细胞瘤SH-SY5Y细胞中对过氧化氢(H2O2)或β-淀粉样蛋白25-35(Aβ25-35)诱导的细胞损伤表现出神经保护活性,范围在正对照的范围内。