Palladium-catalysed reaction of aryl-substituted allylic alcohols with zinc enolates of β-dicarbonyl compounds in the presence of titanium(IV) isopropoxide

Abstract

The reaction of aryl-substituted allylic alcohols 1a–c with Zn(acac)₂ using a catalytic amount of PdCl₂(PPh₃)₂ proceeds efficiently in the presence of lithium chloride and titanium(IV) isopropoxide to give the corresponding acetonylated products 3–5. Similarly, benzoylmethylation and ethoxycarbonylmethylation of 1a and 1b can also be attained by using zinc enolates generated in situ from reactions of zinc chloride with dibenzoylmethane 8b and ethyl benzoylacetate 8c.