Additive-free selective methylation of amines with formic acid over a Pd/In$_2$O$_3$ catalyst

Formic acid is used as the sole carbon and hydrogen source in the methylation of aromatic and aliphatic amines to methylamines. The reaction proceeds via a formylation/transfer hydrogenation pathway over a solid Pd/In$_2$O$_3$ catalyst without the need for any additive.