Copper-Catalyzed C(3+1) Copolymerization of Propargyl Carbonates and Aryldiazomethanes

Controlling the composition and sequence during diazo copolymerization with vinyl or acetylenic monomers is highly desired yet challenging. Here we report a new base-metal-catalysis strategy to address this problem via tandem coupling/polymerization. A selective Cu-catalyzed C(3+1) copolymerization reaction was developed using propargyl carbonates and aryldiazomethanes derived from N-tosylhydrazones as the C3 and C1 building blocks, respectively. This reaction rapidly produces alternating-like poly(1,4-diaryl-2-butyne-1,4-diyl)s (Mn up to 31.0 kg/mol) in a modular fashion, without detectable homopolymer segments. This work provides a new avenue for the synthesis of hydrocarbon polymers through diazo copolymerization.