Catalytic Asymmetric Synthesis of 3-Aminooxindoles: Enantiofacial Selectivity Switch in Bimetallic vs Monometallic Schiff Base Catalysis
Catalytic Asymmetric Synthesis of 3-Aminooxindoles: Enantiofacial Selectivity Switch in Bimetallic vs Monometallic Schiff Base Catalysis
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DOI：
10.1021/ja908906n
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发表时间：
2010-02-03
影响因子：
15
通讯作者：
Shibasaki, Masakatsu
中科院分区：
文献类型：
--
作者：
Mouri, Shinsuke;Chen, Zhihua;Shibasaki, Masakatsu
报道了一种具有四取代碳立体中心的高对映选择性催化不对称合成3-氨基氧吲哚的方法。1-2mol%的高双金属(R)-Ni-2-Schiff碱1催化3-取代氧吲哚与偶氮二甲酸酯的不对称胺化反应生成(R)-产物，产率99-89%，ee 99-87%。在98-80%ee范围内，双金属和单金属席夫碱配合物的对映体选择性发生逆转，单金属(R)-Ni-席夫碱2c生成(S)-产物。还描述了将产物转化为具有光学活性的氧化吲哚，其中带有螺环-β-内酰胺单元和已知的用于AG-041R合成的关键中间体。
A highly enantioselective catalytic asymmetric access to 3-aminooxindoles with a tetrasubstituted carbon stereocenter is described. 1-2 mol % of homobimetallic (R)-Ni-2-Schiff base 1 catalyzed the asymmetric amination of 3-substituted oxindoles with azodicarboxylates to give (R)-products in 99-89% yield and 99-87% ee. Reversal of enantiofacial selectivity was observed between bimetallic and monometallic Schiff base complexes, and monometallic (R)-Ni-Schiff base 2c gave (S)-products in 98-80% ee. Transformation of the products into an optically active oxindole with a spiro-beta-lactam unit and a known key intermediate for AG-041R synthesis is also described.