10.1016/j.mencom.2007.01.008
The research focuses on the asymmetric hydrogenation of methyl levulinate to produce chiral γ-valerolactone using a RuII–BINAP catalyst deposited on a solid organic polyelectrolyte. The study aims to achieve high enantioselectivity while recycling the expensive transition metal catalyst. The experiments involved the use of different polyelectrolytes (PEs) to support the catalyst and maintain its activity over multiple cycles. The reactants included methyl levulinate, the RuII–BINAP–HCl catalyst system, and various polyelectrolytes with different anions. The analyses used to determine the conversion of keto ester 2 and the composition of hydrogenation products were 1H NMR spectroscopy, while the enantiomeric excess of the resulting lactone 4 was assessed using GLC analysis with a specific chiral stationary phase. The study demonstrated that the catalyst could be recycled multiple times with minimal loss in enantioselectivity, highlighting the potential of using solid organic polyelectrolyte carriers for the recycling of transition metal catalysts in asymmetric hydrogenation reactions.
