Convenient synthesis of α-amino amides using low-valent tantalum prepared from TaCl5 and Zn

We have developed a general preparation method of α-amino amides from imines and isocyanates using low-valent tantalum prepared from TaCl5 and Zn in situ. This method was successfully applied to various imines derived from benzaldehyde derivatives with electron-withdrawing or electron-donating substituents, heteroaromatic aldehydes, and an aliphatic, α-branched aldehyde, giving the corresponding α-amino amides in high yields.