Chemoenzymatic synthesis of a mixed phosphine–phosphine oxidecatalyst and its application to asymmetric allylation of aldehydes and hydrogenation of alkenes

Abstract

The chemoenzymatic synthesis of a Lewis basic phosphine–phosphine oxide organocatalyst from a cis-dihydrodiol metabolite of bromobenzene proceeds via a palladium-catalysed carbon–phosphorus bond coupling and a novel room temperature Arbuzov [2,3]-sigmatropic rearrangement of an allylic diphenylphosphinite. Allylation of aromatic aldehydes were catalysed by the Lewis basic organocatalyst giving homoallylic alcohols in up to 57% ee. This compound also functioned as a ligand for rhodium-catalysed asymmetric hydrogenation of acetamidoacrylate giving reduction products with ee values of up to 84%.