Reduction Polymerization of CO with Phenylene Silanes Catalyzed by Single Component B(CF).

CO is an abundant C1 resource but a green-house gas and chemically inert. Thus, its utilization has been a promising but challenging project. Herein, we report the unprecedented polymerization of CO and CH(SiMeH) using B(CF) alone under mild conditions to give poly(silphenylene siloxane) accompanied by releasing CH. The copolymerization can be extended to comonomers of phenylene silanes bearing functional groups. Moreover, it combines with Piers-Rubinsztajn reaction to establish a tandem polymerization system to achieve super thermal resistant poly(siloxane-co-silphenylene siloxane)s. Density functional theory reveals that B(CF) is activated by silanes to form free HB(CF), which is the true active species for CO reducing to borylformate, the rate controlling step of the polymerization procedure. The subsequent multiple reductions of borylformate to CH and the step-growth to poly(silphenylene siloxane)s can be fulfilled by both B(CF) and HB(CF), and the former shows a slightly higher activity. This work opens a new avenue of utilizing CO to fabricate polysiloxanes that is unable to access using current manners.