A Noble-Metal-Free Metal-Organic Framework (MOF) Catalyst for the Highly Efficient Conversion of CO₂ with Propargylic...

Cyclization of propargylic alcohols with CO₂ is an important reaction in industry, and noble-metal catalysts are often employed to ensure the high product yields under environmentally friendly conditions. Herein a porous noble-metal-free framework 1 with large 1D channels of 1.66 nm diameter was synthesized for this reaction. Compound 1 exhibits excellent acid/base stability, and is even stable in corrosive triethylamine for one month. Catalytic studies indicate that 1 is an effective catalyst for the cyclization of propargylic alcohols and CO₂ without any solvents under mild conditions, and the turnover number (TON) can reach to a record value of 14 400. Furthermore, this MOF catalyst also has rarely seen catalytic activity when the biological macromolecule ethisterone was used as a substrate. Mechanistic studies reveal that the synergistic catalytic effect between Cu^I and In^III plays a key role in the conversion of CO₂ .