950171-38-7Relevant articles and documents
Kinetic Resolution of Epoxides with CO2 Catalyzed by a Chiral-at-Iridium Complex
Qin, Jie,Larionov, Vladimir A.,Harms, Klaus,Meggers, Eric
, p. 320 - 325 (2018/11/27)
Chiral-at-metal bis-cyclometalated iridium(III) complexes are introduced as a new class of chiral catalysts for the reaction of epoxides with CO2 to form cyclic carbonates under conditions of kinetic resolution. Reactions are typically performed at room temperature in the presence of 1 mol % of iridium catalyst and 1.5 mol % of tetraethylammonium bromide as the nucleophilic cocatalyst to provide selectivity factors of up to 16.6. A variety of monosubstituted epoxides, including styrene epoxide, epoxides with aliphatic side chains, glycidyl ethers, and a glycidyl ester, are found to be suitable substrates. No polymerization side reaction is observed for any of the investigated substrates.
Enantioselective incorporation of carbon dioxide into epoxides catalyzed by optically active cobalt(II) complexes
Yamada, Wataru,Kitaichi, Yasunori,Tanaka, Hirotaka,Kojima, Tomohide,Sato, Mitsuo,Ikeno, Taketo,Yamada, Tohru
experimental part, p. 1391 - 1401 (2009/06/20)
The enantioselective chemical fixation of CO2 into an epoxide was developed using an optically active ketoimi-natocobalt(II) complex as a chiral Lewis acid. In the presence of a catalytic amount of the cobalt complex and amine base, enantioselective CO2 fixation with an epoxide proceeded with kinetic resolution to afford the corresponding carbonate along with unreacted epoxide, both of which were optically active. To improve their enantioselectivities, the ligand structures of the cobalt complexes and amine bases were examined. Thus, the optimized catalytic system was successfully applied to various epoxides to obtain the corresponding optically active cyclic carbonates and to recover epoxides with good-to-high enantioselectivities.
