Asymmetric Transfer Hydrogenation of (E)-2-[1,2,6,7-Tetrahydro-8H-indeno[5,4-b]furan-8-ylidene]acetaldehyde Using Polymer-Supported Chiral Pyrrolidine Catalyst

The asymmetric transfer hydrogenation of α,β-unsaturated aldehyde with Hantzsch ester catalyzed by polymer-supported chiral pyrrolidine organocatalyst was achieved. The effects of the pyrrolidine substituents and linkage configuration on the catalytic performance were examined in detail. We found that the polymer-supported cis-type chiral pyrrolidine organocatalysts showed high enantioselectivities (up to 99.9%) compared with the corresponding trans analogs and monomers in the reaction. The recovered catalyst was reused without any loss of the catalytic activity.