Intermediate Product-Catalyst Complexes in the Homogeneous Hydrogenation of Styrene Derivatives with Parahydrogen and Cationic RhI Catalysts.

The catalyst-bound intermediate 1 is detected in the homogeneous hydrogenation of styrene derivatives in the presence of cationic RhI catalysts 2. The detachment from the catalyst of the ethylbenzene 3 formed turns out to be slow and possibly rate-determining in some cases.