Integrated “all-in-one” strategy to construct highly efficient Pd catalyst for CO2 transformation

Abstract

The synthesis of high-value chemicals featuring C–C and/or C–heteroatom bonds via CO₂ is critically important, yet efficiently converting thermodynamically stable and kinetically inert linear CO₂ and propargylic amine to the heterocyclic compound 2-oxazolidinone with an integrated catalytic system continues to pose a considerable challenge. Herein, we have designed an “all-in-one” (AIO) palladium (Pd) catalyst (Cat1), distinguished by its co-coordination with acetylglucose (AcGlu) and bis(benzimidazolium) units at the Pd center, which promotes the cyclization of CO₂ and propargylic amine achieving a highest turnover frequency (TOF) of up to 3456 h⁻¹. Moreover, Cat1 demonstrates excellent stability across various temperatures, with its catalytic activity remaining unchanged even after 10 cycles. The catalyst Cat1 simultaneously activates propargylic amine and CO₂, facilitating the formation of N-heterocyclic carbene (NHC)-CO₂ adducts and AcGlu-CO₂ philes from CO₂ in simulated flue gas, a key factor in reaching unprecedented TOF values. The catalytic mechanism was elucidated through quasi-in-situ NMR and ¹³C-isotope labeling experiments. Notably, this is the first instance of an AIO Pd catalyst that enables the simultaneous capture, activation, and catalytic conversion of in-situ activated CO₂ along with propargylic amine. The design strategy of this AIO catalyst introduces a novel approach to overcoming the challenges in the efficient conversion of inert CO₂.