Selective Organocatalytic Preparation of Trimethylene Carbonate from Oxetane and Carbon Dioxide

• Published in: ACS catalysis Vol. 10; no. 10; pp. 5399 - 5404
• Main Authors: Huang, Jin, Jehanno, Coralie, Worch, Joshua C, Ruipérez, Fernando, Sardon, Haritz, Dove, Andrew P, Coulembier, Olivier
• Format: Journal Article
• Language: English
• Published: American Chemical Society 15.05.2020
• Subjects: carbon dioxide; iodine; DFT simulation; organocatalysts; polycarbonate; trimethylene carbonate
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.0c00689

The organocatalytic coupling of oxetanes and carbon dioxide (CO2) offers a sustainable route to poly­(trimethylene carbonate)­s and/or functional six-membered cyclic carbonate monomers. This transformation is more challenging than when using more strained epoxide comonomers and even more so when it is performed using metal-free routes. Herein, we report an organocatalytic oxetane/CO2 coupling procedure that enables the selection of cyclic carbonate or polymer from a common intermediate. Using a novel I2-based binary catalyst system, cyclic carbonate with high selectivity (up to 94%) was obtained at 55 °C, whereas simply changing the temperature to 105 °C yielded the polycarbonate with M n of up to 6.4 kDa, thus showing that either trimethylene carbonate or its concomitant polycarbonate product can be selected solely by the manipulation of the reaction conditions.