Asymmetric Homogeneous Hydrogenation in Flow using a Tube-in-Tube Reactor

In this update, the asymmetric homogeneous hydrogenation of a number of trisubstituted olefins utilizing the recently developed tube-in-tube gas-liquid flow reactor is described. A number of chiral iridium- and rhodium-based catalysts and other parameters such as pressure, solvent, temperature and catalyst loading were screened. The advantage of the flow set-up for rapid screening and optimization of reaction parameters is illustrated. Furthermore, a comparative study using batch conditions aided in the optimization of the flow reaction set-up. The set-up was further modified to recycle the catalyst which prolonged catalytic activity.