Organocerium additions to proline-derived hydrazones: synthesis of enantiomerically enriched amines
作者:Scott E. Denmark、James P. Edwards、Theodor Weber、David W. Piotrowski
DOI:10.1016/j.tetasy.2010.04.042
日期:2010.5
The addition of organocerium reagents (from both organolithium and organomagnesium precursors) to chiral aldehyde hydrazones prepared from 1-aminoproline derivatives has been studied. The additions proceed in good yield and high diastereoselectivity and with good nucleophile (Me, n-Bu, i-Pr, t-Bu, Ph, etc.) and substrate scope (alkyl, alkenyl and aryl). The resulting hydrazines can be converted to
已经研究了将有机铈试剂(来自有机锂和有机镁前体)添加到由1-氨基脯氨酸衍生物制备的手性醛中。添加以高收率和高非对映选择性以及良好的亲核试剂(Me,n- Bu,i- Pr,t- Bu,Ph等)和底物范围(烷基,烯基和芳基)进行。生成的肼可通过氢解(阮内镍)的N–N键裂解或通过Li / NH 3的酰化和裂解而转化为胺。。通过改变取代基以包括更多的配位原子(氧和氮)以及去除配位原子,研究了侧链对非对映选择性的影响。带有2-甲氧基乙氧基甲基的SAMEMP助剂具有最高的非对映选择性。值得注意的是,带有简单甲基和异丁基取代基的助剂也具有很高的选择性。给出了选择性起源的假设。