Sang-Ho Lee

Cobalt(II) and copper(II) complexes supported by 4‐(quinolin‐2‐ylmethyl)morpholine (L) were characterized, and their reactivity toward the ring‐opening polymerization (ROP) of rac ‐lactide ( rac ‐LA) was studied. The use of [LMCl 2 ]/LiO i Pr and [LMCl 2 ]/LiMe (M = Co, Cu) resulted in over 95% conversion within 10 min at 25 °C. The effect of the initiating group and geometry of the metal complexes steered the heterotactic enchainment of the resultant polylactide(PLA). The Co(II)/LiMe system represents the first example of the ROP of rac ‐LA with high heterotactic enchainment ( P r = 0.92) with 98% conversion at 0 °C.