A new procedure for the facile preparation of various vicinal diamines is developed that utilizes diethyl N-(β-bromoalkyl)phosphoramidates 2 easily accessible by ionic addition of diethyl N,N-dibromophosphoramidate (DBPA) to alkenes and cycloalkenes 1. Crude phosphoramidates 2 are readily transformed into the corresponding ammonium ditosylates 5 by sequential azidation, Staudinger reaction with triethyl phosphite, and deprotection by refluxing with p-toluenesulfonic acid in aqueous ethanol. Diamination of cyclohexene and indene proceeds stereospecifically affording cis-1,2-diaminocyclohexane and cis-1,2-diaminoindane, respectively. Open-chain olefins do not react stereospecifically under conventional conditions yielding mixtures of diastereoisomers. Full stereochemical control of azidation can be, however, achieved when β-bromoamine hydrochlorides instead of diethyl N-(β-bromoalkyl)phosphoramidates are used as starting materials for this reaction.
开发了一种轻松制备各种邻位二胺的新程序,该程序利用 N-(β-
溴烷基)
氨基磷酸二乙酯 2,通过将 N,N-二
溴氨基磷酸二乙酯 (
DBPA) 离子加成到烯烃和环烯烃 1 上即可轻松获得。粗
氨基
磷酸酯 2 为通过连续
叠氮化、与
亚磷酸三乙酯的施陶丁格反应以及通过与
对甲苯磺酸在
乙醇水溶液中回流来脱保护,很容易转化为相应的二甲
苯磺酸铵5。
环己烯和
茚的二胺化分别立体定向地产生顺式
1,2-二氨基环己烷和顺式1,2-二
氨基
茚满。 开链烯烃在常规条件下不会发生立体有择反应,产生非对映异构体的混合物。然而,当使用β-
溴胺盐酸盐代替N-(β-
溴烷基)
氨基磷酸二乙酯作为该反应的起始原料时,可以实现
叠氮化的完全立体
化学控制。