Sterically demanding binaphthol-based chiral diboranes for metal-free and isotactic poly(propylene oxide)

Abstract

Chiral diborane polymerization catalysts with 3,3′-disubstituted binaphthol-backbones are presented. These compounds deliver isotactic poly(propylene oxide) from racemic monomer with isotactoc diad (m) and triad (mm) placements of up to 92% and >80%, respectively. The resulting polyether is well-defined, of high molar mass and semi-crystalline.