Reactive & Functional Polymers, Vol.53, No.2-3, 103-112, 2002
Catalytic epoxidations of styrene using a manganese functionalized polymer
Herein we report preliminary results on enantioselective epoxidations of styrene using molecular imprint polymers incorporating an analog of the Jacobsen epoxidation catalyst. We have synthesized molecular imprint polymers (MIPs) containing the pre-catalyst, (R,R)-N,N'-bis-(4-acryloyl-salicylidene)-1,2-cyclohexanediaminato manganese(III) phenylacetate (I), ethyleneglycoldimethacrylate (EGDMA) as the crosslinking agent and varying amounts of styrene as a non-crosslinking monomer and dichloroethane as a porogen. The molecular catalyst (1) shows modest enantioselectivity for styrene epoxidation (21% EE) and the MIPs show less selectivity (4-14% EE). There was no discernable trend in EE when porogen content and crosslinking were varied. The effect of porosity and crosslinking on activity has been explored and optimum conditions of 40-50% porogen and 70% crosslinking have been identified. The MIPs can be reused with no loss of activity for at least three cycles. (C) 2002 Published by Elsevier Science B.V.
Keywords:molecular imprint polymer;enantioselective epoxidation;Jacobsen;supported catalyst;manganese;styrene