高对映选择性有机催化的七元环状亚胺二苯并1,4-氧氮杂卓和丙酮的直接Mannich反应(英文)

用脯氨酸作为催化剂,研究了各种取代的二苯并1,4-氧氮杂卓衍生物类七元环状亚胺和丙酮的直接Mannich反应,该反应能高对映选择得到一系列旋光活性的含有β羰基的七元环状氮杂环化合物(93%–98%ee).用丁酮作为Mannich给体时,能得到专一的区域选择性和96%–97%ee的产物.进一步通过X射线单晶衍射分析其中一个产物的衍生物,确定了产物手性中心绝对构型为R,其它同类型产物绝对构型随后通过化学类比方法推断确认.

Highly enantioselective direct Mannich reaction of seven-membered cyclic imines dibenzo[b,f][1,4]oxazepines with acetone via organocatalysis

Various substituted 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 configuration of the product was assigned to be R by X-ray single crystal analysis of its derivative.