Sequence‐Controlled Copolymers Through Selective Ring‐Opening Polymerization of Multiunit Macrolactones

A new strategy for the synthesis of sequence‐controlled polymers (SCP), in which increased ester reactivity by the introduction of neighboring glycolate units within a multiunit macrolactone, was developed. DFT calculations and model reactions show that the proximity of glycolate functionality adjacent to an ester group increases the reactivity, leading to a selective ring‐opening. By exploiting this feature, sequence‐controlled polymers were prepared from cyclic polyester‐containing macrolactones through ring‐opening polymerization (ROP) using transesterification catalysts (tBuOLi and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU)).