A New Polymer-Anchored Chiral Catalyst for Asymmetric Michael Addition Reactions

(Equation Presented) Monomer (R,R)-3-aza-3-(p-vinylbenzyl)-1,5-diphenyl-1,5-dihydroxypentane (2) when polymerized with styrene and divinylbenzene affords polymers, onto which lithium and aluminum are incorporated via reaction with lithium aluminum hydride. The resulting insoluble polymers containing chiral lithium and aluminum active centers are quite effective for asymmetric Michael addition of nitro compounds, thiols, and amines. The optimized reaction conditions yield Michael adducts in good yield with high enantiomeric excesses.