Abstract
<jats:p>In this work, we synthesized β-diketiminate (NacNac)-supported magnesium complex (DippNacNaciPrMg.THF) (DippNacNac = (2,6-iPr2C6H3)NC(Me)C-(H)C(Me)N(2,6-iPr2C6H3)) (Mg-1) and amidinate-based magnesium complex PhC(NtBu)2MgiPr.THF (Mg-2) and investigated their catalytic performance in the hydroborative reduction of ester, carbonate, and lactide carbonyl functionalities in both monomeric and polymeric substrates. Among the two catalysts, Mg-1 exhibited superior efficiency over Mg-2 in the HBpin-mediated reduction of carbonyl-containing monomers. The catalytic methodology was subsequently extended to the hydroborative depolymerization of carbonyl-containing polymers, including polyesters and polycarbonates. Notably, this represents the first report of NacNac- and amidinate-supported magnesium complexes being employed as catalysts for the hydroborative depolymerization of polyester and polycarbonate materials. Furthermore, the gram-scale depolymerization of polycaprolactone (PCL) was successfully demonstrated, highlighting the potential for future scale-up. A borylated reaction intermediate was also isolated and structurally characterized by single-crystal X-ray diffraction analysis, providing valuable mechanistic insight. Overall, this study demonstrates the significant potential of magnesium-based main-group catalysts as sustainable and efficient systems for the hydroborative depolymerization of carbonyl-containing polymeric materials.</jats:p>