conditions brought about by the steric demands of the 2-adamantyl residue. Similar difficulties were experienced when following the P-borane route of Jugé and Genet, where the 2-adamantyl group was introduced in the initial step. More success was achieved by the borane route when the bulky residue was introduced last by reaction of RLi with the phosphinite complex 13. In this way the ferrocenyl, 1-adamantyl
已经评估了带有大残基的P-手性单膦化合物的不对称合成方法。2- adamantylmagnesium
溴与反应P -chlorooxazaphospholidine 1给出了用叔BuOOH氧化经过两级非对映体的产品; 该小号P异构体,其特征在于X射线和- [R P通过详细的NMR分析异构体。尽管与邻-茴香基
溴化镁反应时异构体2或3的开环令人满意,但通过酸催化的次膦酰胺4的
甲醇解反应,所需反应顺序得以继续进一步使用PhMgBr会导致每个步骤中对映体纯度的降低,因为2-
金刚烷基残基的空间需求会带来更多的强迫条件。当沿着Jugé和Genet的P-
硼烷路线经历类似的困难时,在最初步骤中引入了2-
金刚烷基。当
硼烷最后通过RLi与
次膦酸酯配合物13的反应引入大的残留物时,通过
硼烷途径获得了更大的成功。以此方式,形成同时带有苯基和邻-茴香基残基的
二茂铁基,1-
金刚烷基和
叔丁基膦作为
硼烷配合物。在前两种情况