A Mild and Catalytic Decarboxylation of α-Iminoacids by Tributyl Phosphine.

Abstract α-Iminoacids, prepared from α-keto acids and primary amines, undergo decarboxylation to the corresponding imines by reaction with a catalytic amount of tributylphosphine. No reaction has been observed with α-keto acids or their phenyl-hydrazone, tosyl-hydrazone or oxime derivatives under the same conditions. However, carboxy-azines react rapidly with tributylphosphine and give the corresponding aldazines quantitatively. The mechanism of this reaction is also discussed.