作者:Magnus J. Johansson、Lennart Schwartz、Mohamed Amedjkouh、Nina Kann
DOI:10.1016/j.tetasy.2004.09.023
日期:2004.11
phosphine ligands can be prepared via desymmetrization of prochiral phosphine boranes using s-BuLi·(−)-sparteine complexes. One limitation of this method, however, has been that (+)-sparteine is not easily accessible. Herein, we show that derivatives of another alkaloid, (−)-cytisine, are useful surrogates for (+)-sparteine in the desymmetrization of prochiral phenyl-, cyclohexyl- and tert-butyl dimethyl
可以使用s -BuLi·(-)-sparteine配合物通过前手性膦硼烷的不对称化来制备P-手性膦配体。然而,该方法的局限性在于不容易获得(+)-天冬氨酸。在本文中,我们显示了另一种生物碱(-)-胱氨酸的衍生物在前手性苯基-,环己基-和叔丁基二甲基膦硼烷的去对称化中,对于(+)-天冬氨酸是有用的替代物,最多可生成手性膦硼烷92%ee。还测试了其他手性二胺,但对映选择性不如(-)-胱氨酸衍生物高。