Macromolecules, Vol.54, No.5, 2059-2067, 2021
One-Pot Nonisocyanate Synthesis of Sequence-Controlled Poly(hydroxy urethane)s from a Bis(six-membered cyclic carbonate) and Two Different Diamines
Sequence-controlled synthetic polymers have received increasing interest because of their great potential to develop next-generation functional materials. Here, we report a facile synthesis of a symmetric spiro bis(six-membered cyclic carbonate), 2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-dione (1), its reactivity, and a one-pot, nonisocyanate synthesis of sequence-controlled poly(hydroxy urethane)s (PHUs) from 1 with two different symmetric diamines. The second-order rate constant for the ring-opening addition reaction of one of the two cyclic carbonates of 1 with 1-hexylamine is two orders of magnitude larger than that of the remaining one of the resulting intermediate due to a remarkable difference between their ring strain energies. This difference in the reactivity enables the selective formation of a diurethane-linked bis(six-membered cyclic carbonate) from the reaction of 1 with a diamine (0.5 equiv). The subsequent addition of a different diamine (0.5 equiv) to the same pot affords sequence-controlled PHUs with an ABAC sequence.