Metal-catalysed alkyl ketone to ethyl ketone conversions in chelating ketones via carbon–carbon bond cleavage

8-Quinolinyl alkyl ketones, in which the alkyl group has β-hydrogens, react with various RhI and IrI complexes under ethylene to give, in a catalytic process, 8- quinolinyl ethyl ketone; the same reaction with 8-quinolinyl phenyl ketone produces styrene via ethylene insertion into a rhodium–phenyl bond and β-elimination of the resulting phenylethyl complex.