Cycloaddition of carbon dioxide and epoxides catalyzed by rare earth metal complexes bearing a Trost ligand

• Published in: New journal of chemistry Vol. 45; no. 29; pp. 1396 - 1313
• Main Authors: Cheng, Jun, Lu, Chengrong, Zhao, Bei
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 07.08.2021
• Subjects: Carbon dioxide; Carbonates; Chemical synthesis; Coordination compounds; Crystallography; Cycloaddition; Ligands; NMR; Nuclear magnetic resonance; Rare earth elements; Samarium; Tetrabutylammonium bromide; Yttrium
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d1nj02460d

A series of rare earth metal complexes (Sm ( 1 ), Eu ( 2 ), Y ( 3 ), Yb ( 4 ), and Lu ( 5 )) based on Trost ligands were synthesized and well characterized, and catalyzed the cycloaddition of carbon dioxide and epoxides successfully. The combination of 1 mol% Sm-based complex 1 with 2 mol% tetrabutylammonium bromide (TBAB) was proved to be the optimal catalyst system for the formation of the monosubstituted cyclic carbonate at 70 °C under the atmospheric pressure. While for the more challenging disubstituted epoxides, the adduct cyclic carbonates were successfully obtained when the pressure of CO 2 was elevated to 0.7 MPa. Rare earth metal complexes containing Trost ligands were used to catalyze the cycloaddition reaction of epoxides with CO 2 . A series of epoxides were successfully converted into the corresponding cyclic carbonates under mild conditions.