dibenzo[ b,f ][ 1,4 ]oxazepines as seven-membered cyclic imines underwent a highly enantioselective direct Mannich reaction with acetone when catalyzed by proline. These reactions gave a range of optically active β-carbonyl seven-membered N -heterocycles with excellent enantioselectivity (93%–98% ee). With 2-butanone as a Mannich donor, the single regioselective product was obtained with 96%–97% ee. The absolute
摘要 各种取代的二苯并[ b, f ][ 1,4 ]氧氮杂作为七元环
亚胺,在脯
氨酸催化下与
丙酮发生高度对映选择性的直接曼尼希反应。这些反应产生了一系列具有优异对映选择性 (93%–98% ee) 的光学活性 β-羰基七元 N-杂环。以 2-
丁酮作为曼尼希供体,获得了具有 96%–97% ee 的单一区域选择性产物。通过对其衍
生物的 X 射线单晶分析,产物的绝对构型被指定为 R。