A highly efficient and general -monomethylation of functionalized primary amines via formylation--borane:methyl sulfide reduction

Formylation of functionalized primary aromatic and aliphatic amines with acetic formic anhydride (AFA) followed by borane:methyl sulfide reduction in the same pot affords the corresponding N-methylamines in excellent isolated yields, uncontaminated bybis alkylation; the reaction sequence is applicable to even very weakly basic and sterically hindered amines.