Regioselective deuterium labelling of aromatic acids, amides and amines using group VIII metal catalysts

Ortho‐deuterated arylcarboxylic acids and their sodium salts may be prepared with high regioselectivity by isotopic exchange with deuterium oxide in the presence of a range of commercially available group VIII metal complexes. When rhodium trichloride trihydrate is employed a range of arylcarboxamides and arylmethanamines are also selectively labelled at the ortho‐positions.