Study on the Synthesis of Metalloporphyrin and Multi-chiral Schiff-base Complexes and Their Catalytic Properties in the Coupling Reaction of Carbon Dioxide with Epoxides
|Keywords||Metalloporphyrins Multiple chiral Schiff base cobalt complexes Phenyl trimethyl ammonium bromide (PTAT) Carbon dioxide Epoxy compounds Coupling reaction|
Chemical fixation can take advantage of inexpensive carbon resources and reduce greenhouse gas carbon dioxide , so either from the economy or from the environment are subject to the attention of the people . The cyclic carbonate is one of the fixed product of the carbon dioxide chemical , cyclic carbonate widely used in the synthesis of organic intermediates , aprotic polar solvents , in biomedical precursor , as well as engineering plastics raw materials . Catalyzed asymmetric synthesis is one of today 's Organic Chemistry frontier provides a new opportunity for the preparation of enantiomerically pure chiral drugs and chiral material . An optically active cyclic carbonic ester as the chiral starting material , can be used for the synthesis of optically active diol compounds , and so on . The papers from each of the four aspects of the synthesis of the cyclic carbonate optically active cyclic carbonates . (1) Metal porphyrin -catalyzed coupling reaction of carbon dioxide with the epoxy compound , respectively, discussed the different catalyst , co-catalyst , a counter ion, the influence of metal ions on the reaction , research found that when using the Co (III ) TPPOAc / PTAT catalytic system, at room temperature , the epoxy compound substituted by the various end can be obtained in high yield the corresponding cyclic carbonate . (2) as catalyst ruthenium porphyrin complex Ru (TPP) ( the PPh 3 < / sub >) 2 sub > , PTAT as co-catalysts , EDA is the cocatalyst without adding any solvent 333K, 667KPa under mild conditions , it is possible to make the carbon dioxide and an epoxy compound to the coupling reaction , to give the corresponding cyclic carbonate in a high yield . (3) as a starting material , a chiral amino acids and the chiral binaphthol After several reaction synthesis of chiral macrocyclic porphyrin compounds , with the PTAT Preliminary Investigation of the Chiral Synthesis of the cyclic carbonate , but only moderate ee values ??. (4) to the chiral binaphthol as a starting material , synthesis of more than 33 chiral compounds of the Schiff base , including 27 novel compounds were applied to the carbon dioxide with the epoxy compound and trivalent metal catalyst asymmetric cycloaddition reactions , the research found that when the dual - catalyst system the 2b/9b PTAT formed catalyst the cyclopropene carbonate ee value at 0 ℃ can reach 87 % and 90% at -20 ℃ catalyst 9b as a catalyst , ring propylene carbonate ee values ??of up to 95% .