Sequence-controlled polyhydroxyurethanes with tunable regioregularity obtained from biobased vicinal bis-cyclic carbonates

Polyhydroxyurethanes (PHUs) are phosgene and isocyanate-free polyurethanes (PUs) that are foreseen as a promising alternative to conventional polyurethanes (PUs). Herein, we use enantiopure bis-5CC obtained from the direct carbonatation of sugar-based butadiene tetraols that are enantiopure themselves, namely (i) meso-erythritol and (ii) its (S,S) diastereoisomer, (L)-threitol. For both erythritol dicarbonate (EDC) and threitol dicarbonate (TDC), the kinetics rate constant of the aminolysis of the dicarbonate is two orders of magnitude larger than that of the mono-carbonate resulting from the first aminolysis reaction. We use this feature to develop a one-pot, two step polymerization procedure offering sequence-controlled PHUs.