organocatalyzed asymmetric reaction of phenacyl halides with coumarin‐based dihydrobenzothiazoles was developed to afford cis‐2,3‐disubstituted 3,4‐dihydro‐2H‐benzothiazines. This method provides a one‐step and highly diastereoselective route to a wide variety of coumarin‐based 3,4‐dihydro‐2H‐benzothiazines using the cheap and commercially available Cinchona alkaloid quinine hydrochloride.
与
香豆素系dihydrobenzothiazoles
苯甲酰
甲基卤化物的有效和organocatalyzed不对称反应物展开,获得顺式- 2,3-二取代的3,4-二
氢-2- ħ -benzothiazines。该方法使用便宜的市售Cinchona
生物碱奎宁盐酸盐为多种基于
香豆素的3,4-二
氢-2 H-
苯并
噻嗪提供了一步式且高度非对映选择性的途径。