Reductive Amination of Acetals by Anilines in the Presence of Triethylsilane and Iodine

A mild and efficient method for N-alkylation of aromatic amines with various acetals such as aryl, alkyl, cyclic and acyclic acetals was developed. A number of aromatic amines bearing electron-donating or electron-withdrawing substituents were directly alkylated by acetals with excellent yields. The method uses a catalytic amount of I2 and triethylsilane as the hydride source without a metal present. Monoalkylation with excellent chemoselectivity was observed.