Kinetic resolution of pent-4-ene-1,3-diol by Pd(ii)-catalysed oxycarbonylation in ionic liquids

Abstract

The first example of the use of ionic liquids as reaction media in an asymmetric Pd(II)-catalysed oxycarbonylation was investigated. Based on a ligand screening, the chiral box-type ligands were successfully used in the Pd(II)-promoted bicyclisation of pent-4-ene-1,3 diol (±)-1. The kinetic resolution of (±)-1 in the presence of a chiral catalyst, p-benzoquinone and acetic acid in ionic liquids under a carbon monoxide atmosphere afforded enantioenriched 2,6-dioxabicyclo[3.3.0]octane-3-ones (S,S)-2 (80% ee) and (R,R)-2 (57% ee).