Turbo-Grignard Reagent Mediated Polymerization of Styrene under Mild Conditions Capable of Low Đ and Reactive Hydrogen Compatibility

To develop novel polymerizations capable of manipulating low molecular weight distribution (Đ) through novel polymerization species rather than radical, anionic, or cationic species is highly desirable and challenging, which will enable polymer chemistry with a new polymerization mode and synthetic route. Grignard reagent mediated alkene polymerization is generally regarded as anionic polymerization that is not applicable for nonpolar monomers like styrene (St). Here, the turbo-Grignard reagent mediated polymerization of St is demonstrated to exhibit intriguing all-in-one characteristics of covalent–anionic–radical polymerization. Under mild conditions, polystyrenes with narrow molecular weight distribution can be obtained with over 99% monomer conversion by using a series of turbo-Grignard reagents (RMgX·LiCl) as initiators, including alkylMgCl·LiCl, BnMgCl·LiCl, and allylMgCl·LiCl. In comparison with traditional Grignard reagent mediated reactions and polymerizations exhibiting zero tolerance with reactive hydrogen, this turbo-Grignard reagent mediated polymerization exhibits compatibility with reactive hydrogen under mild conditions and expands the library of polymerization with an intriguing turbo-Grignard reagent mediated all-in-one covalent, anionic, and radical polymerization mode.