Synthesis of Chiral Trifluoromethyl Benzylamines by Heterogeneous Catalytic Reductive Amination
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- 作者：Sujaya Dasgupta ; Elena Morzhina ; Christian Schäfer…
- 刊名：Topics in Catalysis
- 出版年：2016
- 出版时间：August 2016
- 年：2016
- 卷：59
- 期：13-14
- 页码：1207-1213
- 全文大小：508 KB
- 刊物主题：Catalysis; Physical Chemistry; Pharmacy; Industrial Chemistry/Chemical Engineering; Characterization and Evaluation of Materials;
- 出版者：Springer US
- ISSN：1572-9028
- 卷排序：59
文摘
The synthesis of several chiral α,α,α-trifluoromethylbenzylamines by an environmentally benign exclusively heterogeneous catalytic method is described. The procedure is based on trifluoromethyl acetophenones as starting materials. The commercially available inexpensive K-10 montmorillonite was applied for the synthesis of imines from the α,α,α-trifluoromethyl ketones and chiral α-methylbenzylamines. The diastereoselective hydrogenations of the imines were carried out in the presence of 5 % Pd/BaCO3 catalyst followed by the hydrogenolysis of the benzylic group under acidic conditions to give the respective chiral amines in good yields. The diastereomeric excess achieved in the hydrogenation was further enhanced by a secondary kinetic resolution during the hydrogenolysis step ensuring good to excellent enantioselectivities. The simplicity of this method makes it an alternative synthetic procedure for the preparation of both enantiomers of substituted chiral α,α,α-trifluoromethylbenzylamines.KeywordsReductive aminationK-10 montmorilloniteHeterogeneous catalysisDiastereoselective hydrogenation2,2,2-Trifluoro-1-phenylethylaminesPalladiumHydrogenolysis