Enantioselective addition of phenylacetylene to aldehydes catalyzed by polymer‐supported titanium(IV) complexes of β‐hydroxy amides

Abstract

A series of polymer-supported chiral beta-hydroxy amides and C(2)-symmetric beta-hydroxy amides have been synthesized and successfully used for the enantioselective addition of phenylacetylene to aldehydes. High yields (up to 93%) and enantioselectivities (up to 92% ee) were achieved by using polymer-supported chiral beta-hydroxy amide 4b. The resin 4b is reused four times, giving the product with enantioselectivity 80% ee. Fortunately, it is found that this heterogenous system is suitable not only for aromatic aldehydes but also aliphatic aldehyde.