SaBOX/Copper Catalysts for Highly Syndio-Specific Atom Transfer Radical Polymerization of Methyl Methacrylate

SaBOX/copper catalysts have been developed, giving a highly syndio-specific (triad syndiotacticity rr over 90%) and well-controlled (molecular weight distribution Đ = 1.1–1.4) atom transfer radical polymerization (ATRP) of methyl methacrylate. The substituents on the bisoxazoline (BOX) scaffold significantly affect the polymerization rate, molecular weight, and stereoselectivity. The side arms installed on the bridge carbon of BOX have been proven to strongly influence both the activity of the catalyst and the tacticity of the resulting polymers, paving an alternative way for the control of stereoselectivity in ATRP. X-ray structural determination and the Eyring approach were employed to obtain insights into the scaffold and side arm effects on catalyst performance.