The Acceleration of the Rearrangement of α-Hydroxy Aldimines by Lewis or Brønsted Acids

Abstract

An efficient method was developed for the synthesis of α-amino ketones from α-hydroxy imines. The reaction occurs through an α-iminol rearrangement involving the migration of a substituent of the carbinol carbon to the imine carbon. The optimal catalysts were found to be silica gel or montmorillonite K 10, which effected migration of a variety of aryl and alkyl substituents in high yields. The rearrangement can also be carried out on imines generated in situ from aldehydes and amines in essentially the same yields as those from the preformed imines.

Key words

iminol rearrangement - silica gel - montmorillonite - catalysis - amino ketone - hydroxy imines

• References and Notes

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For recent examples of other methods for the synthesis of α-amino ketones, see:
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