Polymer-Supported Chiral Lewis Base Catalysts

Significance

Novel polymer-supported chiral phosphoramides were used as a Lewis base catalyst 1 in the asymmetric addition of allyltrichlorosilane to benzaldehyde. The allylation of benzaldehyde proceeded in the presence of the catalyst 1 (10 mol% of phosphoramide unit) at -78 °C for six hours in dichloromethane to give 1-phenyl-but-3-en-1-ol in up to 84% yield with enantiomeric excesses of 63%. The reaction was accelerated by the addition of five equivalents of ethyldiisopropyl­amine. Catalyst 1 was found to be more effective its homogeneous counterpart.