Diethylene Glycol/NaBr Catalyzed CO ₂ Insertion into Terminal Epoxides: From Batch to Continuous Flow

CO2 insertion reactions on terminal epoxides (styrene oxide, 1,2-epoxyhexane and butyl glycidyl ether) were performed in a binary homogeneous mixture comprising NaBr as the nucleophilic catalyst diethylene glycol (DEG) both solvent activator (cation coordinating agent). The reaction protocol was initially studied under batch conditions either autoclaves glass reactors: quantitative formation of cyclic organic carbonate products (COCs) achieved at T=100 °C p0(CO2)=1–40 bar. process then transferred to continuous-flow (CF) mode. effects parameters (T, p(CO2), loading, flow rates) using microfluidic reactors capacities variable from 7.85 ? 10?2 0.157 cm3. Albeit CF took place T=220 120 bar, improved productivity allowed recycle through semi-continuous extraction procedure. For model case 1,2-epoxyhexane, (non-optimized) rate corresponding carbonate, 4-butyl-1,3-dioxolan-2-one, increased up 27.6 mmol h?1 equiv.?1, value 2.5 higher than Moreover, NaBr/DEG reusable without loss performance for least 4 subsequent CF-tests.