Binaphthol-derived phosphoric acids as efficient chiral organocatalysts for the enantiomer-selective polymerization of rac-lactide.

A high enantiomer-selectivity for the polymerization of rac-lactide was achieved using chiral binaphthol-derived monophosphoric acids as organocatalysts. During the polymerization, d-lactide (DLA) preferentially polymerized via kinetic resolution with the maximum selectivity factor (kD/kL) of 28.3. The selective polymerization of DLA was derived from a dual activation, i.e., monomer activation and chain-end activation.