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

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 CO 2 and epoxide with CS 2 were also examined under the same reaction conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)