Chemical Fixation of Carbon Dioxide Co‐Catalyzed by a Combination of Schiff Bases or Phenols and Organic Bases

Abstract

Binaphthyldiamino, ethyldiamino and cyclohexyldiamino Schiff bases can catalyze the reaction of epoxides with carbon dioxide in the presence of catalytic amounts of various organic bases to give the corresponding cyclic carbonates in high yields. The simplest binaphthyldiamino Schiff base, derived from the reaction of binaphthyldiamine with salicylaldehyde, gave the highest yield of cyclic carbonate. This catalytic system can be further simplified by use of a phenol instead of the Schiff base to give the corresponding cyclic carbonates in high yields as well. Mechanistic insights were obtained based on a deuterium labeling experiment. The reaction of aziridines with CO2 and epoxide with CS2 were also examined under the same reaction conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Brønsted Acidic Ionic Liquids Mediated Metallic Salts Catalytic System for the Chemical Fixation of Carbon Dioxide to Form Cyclic Carbonates

“…When the catalyst of Brønsted acidic ionic liquidsZnBr 2 is compared with other catalyst system in the literature [31,46,57] for the coupling of carbon dioxide and epoxides, these reported values of TOF are lower than that obtained in the present work. The reaction temperature for the PhOH-organic base catalyst [46], but the reaction pressure is higher by 3.57 MPa than the pressure in the present work and the organic solvent of 1,2-dichloroethane was needed.…”

“…The reaction temperature for the PhOH-organic base catalyst [46], but the reaction pressure is higher by 3.57 MPa than the pressure in the present work and the organic solvent of 1,2-dichloroethane was needed. A high yield of propylene carbonate is obtained with tetrahaloindate(III)-based ionic liquids catalyst [57] at low carbon dioxide pressure (100 psi); however, the high loading of ionic liquid was necessary.…”

“…Until now, the acid-functionalized ionic liquids have been successfully used as catalyst and/or solvent for the protection of carbonyl groups [40], dimerization of a-methylstyrene [41], the Prins reaction [42], reductive amination of carbonyl compounds [43], selective oxidation of alcohols [44] and hydroamination of alkenes [45]. In previous literature, Shi et al [46] found that phenol could act as a Brønsted acid to accelerate the ring opening reaction of epoxides by the hydrogen bond in the reaction of carbon dioxide and epoxides to form cyclic carbonates. In the present work, the COOH-and SO 3 H-functionalized Brønsted acidic ionic liquids were synthesized ( Fig.…”

Sustainable conversion of carbon dioxide: the advent of organocatalysis

“…Moreover, cyclic carbonates, which can be easily produced via direct CO 2 coupling reactions with epoxides and/or oxetanes, are conveniently used as substrates for this type of reaction. Organocatalysts other than ILs including phenolic compounds 50 and NHCs 64 also have found applicability in this transformation but similar selectivity issues, as aforementioned, have been encountered. The synthesis of five-membered cyclic carbonates and carbamates has been a highly active research area over the last five years.…”

Coupling of carbon dioxide with neat propylene oxide catalyzed by aminebisphenolato cobalt(II)/(III) complexes and ionic co-catalysts

“…In contrast to these examples, cobalt(II) salen complexes containing a binapthyl backbone in the presence of neutral Lewis base co-catalysts perform cycloaddition reactions of carbon dioxide with epoxides to yield cyclic carbonates with TON 800-913 [10]. Subsequently, it was shown that in these examples the phenolic ligands themselves could perform such reactions and similar TONs could be obtained without the need for a metal [11]. A range of bifunctional cobalt-salen complexes have been reported that under the appropriate conditions either copolymerize or form cyclic carbonates from propylene oxide and carbon dioxide [12][13][14][15].…”