Towards a Practical Brønsted Acid Catalyzed and Hantzsch Ester Mediated Asymmetric Reductive Amination of Ketones with Benzylamine

Abstract

We report the use of benzylamine as the amine component in Hantzsch ester mediated and chiral Brønsted acid catalyzed enantioselective reductive aminations of ketones. The method is noteworthy because the benzyl group is easily removable, and amine product purification is achieved through Hantzsch ester oxidation product removal via basic hydrolysis.

Key words

benzylamine - Hantzsch ester - reductive amination - ­organocatalysis - chiral amines - Brønsted acids

References and Notes

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8

The absolute configuration of amine 5a was established via comparing the HPLC chromatogram with authentic sample of (S)-5a.