Chemoenzymatic Dynamic Kinetic Resolution of Axially Chiral Allenes

At the palladium: Dimeric palladium bromide complexes bearing monodentate N-heterocyclic carbene ligands have been identified as efficient catalysts for the chemoselective racemization of axially chiral allenyl alcohols. In combination with porcine pancreatic lipase as biocatalyst, a dynamic kinetic resolution has been developed, giving access to optically active allenes in good yield and high enantiomeric purity (see scheme).