Novel chemoenzymatic oxidation of amines into oximes based on hydrolase-catalysed peracid formation?

Organic & Biomolecular Chemistry Pub Date: 2017-03-28 DOI: 10.1039/C7OB00374A

Abstract

The efficient transformation of benzylamines into the corresponding oximes has been described by means of a chemoenzymatic process. This strategy is based on a two-step sequence developed in one-pot at 30 °C and atmospheric pressure. First, the formation of a reactive peracid intermediate occurs by means of a lipase-catalysed perhydrolysis reaction, and then this peracid acts as a chemical oxidising agent of the amines. A total of nine ketoximes were isolated in high purity after a simple extraction protocol (90–98% isolated yield), while for the eleven synthesised aldoximes a further column chromatography purification was required (71–82% isolated yield). In all cases excellent selectivities were attained, offering a practical method for amine oxidation in short reaction times (1 hour). The environmental impact of the process was analysed and compared with a recently published alternative chemical synthesis, finding for this metric a good E-factor value.

Graphical abstract: Novel chemoenzymatic oxidation of amines into oximes based on hydrolase-catalysed peracid formation
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