Ring-opening polymerization (ROP) of maleic anhydride (MA) or L-Lactide (L-LA) with tert-butyl glycidyl ether (tBGE) were carried out in the presence of Ti and Zr complexes of benzoxazole substituted 8-hydroxyquinoline ligands (1a-3a and 1b-3b), delivering nearly alternative P(tBGE-co-MA) and block-like P(tBGE)-b-PLLA co-polymers with high molecular weight (M-n) and narrow to broad molecular weight distributions (M-w/M-n). The molecular structures of the Ti and Zr complexes (1a and 3b) were confirmed by single-crystal X-ray diffraction analysis. The Zr complex 3b exhibited superior reactivity and produced copolymers within one hour at 80 degrees C in dry toluene (M-n,M-GPC = 14-40 Kg mol(-1) and M-w/ M-n= 1.19-1.55). In case of P(tBGE-co-MA) copolymer synthesis, the polymer arm with tBGE fraction was building faster (82-100 unit%) compared to MA (52-99 unit%). In contrast, incorporation of L-LA was higher (82-99 unit%) compared to tBGE insertion (20-60 unit%) in P(tBGE)-b-PLLA copolymer synthesis. (C) 2017 Elsevier Ltd. All rights reserved.