Recyclable catalyst for the asymmetric Henry reaction based on functionalized imidazolidine-4-one-copper(II) complexes supported by a polystyrene copolymer

Imidazolidine-4-one derivatives were anchored by the thiol-ene click reaction to a swellable pearl-like polystyrene copolymer and their complexes with Cu(II) acetate were utilized as recyclable heterogeneous catalysts for the Henry reaction of substituted aldehydes with nitromethane. The corresponding 2-nitroethanols were mostly obtained in high yields (65-99%) and with enantioselectivities of up to 92% ee. After a fivefold recycling of the catalyst, the decrease in enantioselectivity was negligible (Delta 3% ee). (C) 2015 Elsevier Ltd. All rights reserved.