Catalytic Acylcyanation of Imines with Acetylcyanide

Abstract

Aldimines react with acetyl cyanide in the presence of a catalytic amount of a thiourea catalyst to give the corresponding N-acetylated amino nitriles in high yields. The scope of the reaction is broad and both aromatic as well as aliphatic aldimines can readily be used.

Key words

acylcyanation - α-amino nitrile - Brønsted acid catalysis - organocatalysis - acetyl cyanide

References and Notes

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6

Under our reaction conditions using triethylamine as the catalyst only 4% conversion of imine 1a to product 4a was achieved.

9

Even in the absence of catalyst, significant conversion (>30%) to the product was observed.

10

Using the chiral phosphoric acid catalyst 3,3′-bis[(2,4,6-tris(isopropyl)phenyl]-5,5′,6,6′,7,7′,8,8′-octahydro-1,1-binaphthyl hydrogen phosphate (10 mol%) at -40 °C, product 4a was obtained in 92% yield and 69:31 er.