Highly Active and Readily Accessible Proline‐Based Dizinc Catalyst for CO2/Epoxide Copolymerization. Issue 65 (27th October 2017)

• Record Type: Journal Article
• Authors: Schütze, Mike; Dechert, Sebastian; Meyer, Franc
• Is Part Of: Chemistry. Volume 23:Issue 65(2017)
• Page Start: 16472
• Page End: 16475
• Publication Date: 2017-10-27
• Subjects: CO2 activation -- copolymerization -- cyclohexene oxide -- epoxide -- green chemistry -- low pressure polymerization; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201704754
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: In the pursuit of CO2 ‐based materials, the development of efficient catalysts for the alternating copolymerization of CO2 and epoxides to give polycarbonates is receiving particular attention. Desirable attributes for such catalysts are high copolymerization activity at low CO2 pressure, as well as chemo‐ and stereocontrol over the formed polymer. Here, we report a novel chiral zinc catalyst that can be isolated in 97 % yield from commercial sources, and that produces polycarbonates selectively from neat cyclohexene oxide under 1 bar of CO2 pressure at temperatures above 50 °C. At 80 °C reaction temperature, TONs of 1684 and initial TOFs up to 149 h −1 were measured, producing an isotactic‐enriched polycarbonate with a probability P m of 65 % for the formation of a meso diad. Insight into the dinuclear nature of the active species and the copolymerization progress has been gained from structural and spectroscopic studies. Abstract : New chiral dinuclear zinc complex, based on a readily available proline‐derived tridentate {ONO} ligand, shows very high CO2 /epoxide copolymerization activity at 1 bar CO2 and produces an isotactic‐enriched polycarbonate with very high chemoselectivity.