“…On the other hand, tailored dinucleating ligands have been designed in order to assure the spatial proximity of two zinc centers, a fundamental requirement for their cooperativity. Among the related complexes, active catalysts in the synthesis of PLA are bis(diamino)‐ and bis(diimino)‐phenolate dinuclear zinc complexes reported by Tolman and Williams [10] and subsequently by Mehrkhodavandi, [11] various dizinc complexes bearing NNO‐scorpionate ligands explored by Otero, [12] in addition to xanthene‐bridged bis(iminophenolate), [13] calixarene, [14] bis(salalen) [15] and bis(iminopyrrolide) [16] dizinc complexes. To date, the most active catalyst for the ring‐opening polymerization of lactide in solution is a bis(imino)diphenylamido dizinc complex, reported in 2016 by Williams and Brooker, [17] which showed TOF up to 60000 h −1 and worked efficiently also under immortal conditions or at very low catalyst loading.…”