Enantioselective hydrogenation in ionic liquids: Recyclability of the [Rh(COD)(DIPAMP)]BF4 catalyst in [bmim][BF4]

Asymmetric hydrogenation of (Z)-α-acetamidocinnamic acid and methyl-(Z)-α-acetamidocinnamate by [Rh(COD)(DIPAMP)][BF4] catalyst was studied in ionic liquid/isopropanol two-phase catalytic system. In this system 97–100% conversion was achieved and the enantioselectivity values were over 90%. Application of [bmim][BF4] ionic liquid made it possible to recycle the catalyst in consecutive cycles. After four cycles, neither significant conversion nor enantioselectivity decrease was observed.