Hydrogenation of quinoline by rhodium catalysts modified with the tripodalpolyphosphine ligand MeC(CH2PPh2)(3)

As part of our modelling studies of the hydrodenitrogenation of N-heterocyc les contained in raw oil materials, we investigated the selective hydrogena tion of quinoline to 1,2,3,4-tetrahydroquinoline by rhodium catalysts modif ied with the tripodal polyphosphane ligand MeC(CH2PPh2)(3). Experiments in standard autoclaves and in high-pressure sapphire NMR tubes, kinetic and is otope labelling studies, and independent reactions with isolated compounds have contributed to the elucidation of the catalytic mechanism as well as i dentification of the electronic requisites of thc metal catalyst for select ive and efficient hydrogenation.