Enantioselective Synthesis and Application to the Allylic Imidate Rearrangement of Amine‐Coordinated Palladacycle Catalysts of Cobalt Sandwich Complexes
作者:Doyle J. Cassar、Gennadiy Ilyashenko、Muhammad Ismail、James Woods、David L. Hughes、Christopher J. Richards
DOI:10.1002/chem.201302922
日期:2013.12.23
8 equiv) is a catalyst for the allylic imidate rearrangement of an (E)‐N‐aryltrifluoroacetimidate (up to 83 % ee), and this catalyst system is also applicable to the rearrangement of a range of (E)‐trichloroacetimidates (up to 99 % ee). This asymmetric efficiency combined with the simplicity of catalyst synthesis provides accessible solutions to the generation of non‐racemic allylic amine derivatives
(η 5 -( N , N -二甲氨基甲基)环戊二烯基)(η 4 -四苯基环丁二烯)钴与四氯钯酸钠和( R ) -N -乙酰基苯丙氨酸反应得到平面手性环钯二-μ-氯化双[(η 5 - ( S p )-2-( N , N-二甲基氨基甲基)环戊二烯基,1- C ,3′- N )(η 4 -四苯基环丁二烯)钴]二钯[( S p )-Me 2 -CAP-Cl],92 % ee和 64% 的产率。通过纯化单体 ( R )-脯氨酸加合物并转化回氯化物二聚体,实现对映体纯度 (>98% ee )。AgOAc 处理得到 ( S p )-Me 2 -CAP-OAc,将其应用于不对称转环钯化(高达 78 % ee)。( R )-N-乙酰基苯丙氨酸介导的钯化方法也适用于相应的N , N-二乙基(82% ee,产率 39%)和吡咯烷基(>98% ee,产率 43%)钴夹心配合物。5 mol % 的后者 [( S p