Insights on recyclable catalytic system composed of task-specific ionic liquids for the chemical fixation of carbon dioxide

Abstract

Several imidazolium ionic liquids display high efficiency as catalysts for the sequential oxidation of alkene and carboxylation of epoxide.

Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide by Using Organocatalysts

“…Similar studies were performed by Dupont et al., who evaluated the nature of the cation and anion in a series of 21 imidazolium‐based catalysts 89. In this report, a synergistic effect of the acidic and basic sites of the imidazolium salt was confirmed.…”

A DFT study on the insertion of CO2 into styrene oxide catalyzed by 1‐butyl‐3‐methyl‐Imidazolium bromide ionic liquid

“…Interestingly, for route II, there is no formation of an alcohol species as detected for route I , a fact that was also observed experimentally for the condensed phase in the presence of a small quantity of water . Despite of this fact, when a higher amount of water was added to the system, formation of styrene 1,2‐diol was observed as a by‐product.…”

“…They also verified the reaction barriers in the gas phase are insensitive to the length of the alkyl side chain, contrary to experimental results in condensed phase, and they attributed this behavior to bulk effects. In a previous work, it was shown experimentally that for a series of ILs both cation and anion play an important role in the catalysis as well as the nucleophilic strength of the anion dictates the yield and selectivity of the reaction considering the same cation . Preliminary density functional theory (DFT) results also indicated the activation of the epoxide ring by both imidazolium cation and bromide.…”

“…Nevertheless, the highly oxidized state and thermodynamic stability of carbon dioxide make it very stable, requiring reactive nucleophilic or electron‐donating compounds and reactive catalysts. In light of this, while many techniques for the capture and utilization of CO 2 are available, the catalyzed cycloaddition of CO 2 to epoxides has been seen as an attractive synthetic route to form useful five‐membered cyclic carbonates (Figure ) . These formed cyclic carbonates have many applications essentially as electrolytes, high boiling and aprotic polar solvents, fuel additives, paint strippers, adhesives, starting materials for polymerization reactions, and intermediates in organic synthesis (For reviews on CO 2 conversion in cyclic carbonates and on organic carbonates, see ).…”

Efficient Catalytic System Involving Molybdenyl Acetylacetonate and Immobilized Tributylammonium Chloride for the Direct Synthesis of Cyclic Carbonates from Carbon Dioxide and Olefins

“…44% selectivity to SC at 57% styrene conversion was achieved in the reaction conducted with chromium-organic frameworks and TBAB as a catalyst system, at temperatures of 25-100 °C and a CO 2 pressure of 8-100 bar [16]. The ionic liquid 1-butyl-3-methylimidazolium bromide was used in a one-pot reaction (150 °C, 0.5 MPa of CO 2 , 6 h) allowed to obtain SC with 40% selectivity at 90% conversion of styrene, whereas SC was obtained with a selectivity of 63% at 99% conversion of styrene in the reaction conducted in a single reactor under different conditions for each step (epoxidation step: 100 °C, 16 h, cycloaddition step: 150 °C, 0.5 MPa, 6 h) [17]. Recently, polyoxometalate-based homochiral metal-organic frameworks were used as catalysts for enantioselective synthesis of cyclic carbonates in the presence of TBHP as an oxidant [18].…”