Column preparation high temperature silylation

While the Lewis acid-catalyzed reactions of imines with silyl enolates are one of the most efficient methods for the preparation of b-amino esters, many imines are hygroscopic, unstable at high temperatures, and difficult to purify by distillation or column chromatography. It is desirable from a synthetic point of view that imines, generated in situ from aldehydes and amines, immediately react with silyl enolates and provide b-amino esters in a one-pot reaction. However, most Lewis acids cannot be used in this reaction because they decompose or deactivate in the presence of the amines and water that exist during imine formation. Due to the unique properties of Ln(OTf)3, their use as catalysts for the above one-pot preparation of b-amino esters from aldehydes was planned. 

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