Carbon Dioxide Fixation Catalyzed Metals Complexes

Carbon Dioxide Fixation Catalyzed by Metal Complexes Koji Tanaka... 

CARBON DIOXIDE FIXATION CATALYZED BY METAL COMPLEXES... 

Leitner, W. Carbon-Dioxide as a Raw-Material - The Synthesis of Formic-Acid and Its Derivatives from CO2, Angew. Chem. Int. Ed. Engl. 1995, 34, 2207. (c) Tanaka, K. Carbon dioxide fixation catalyzed by metal complexes Adv. Inorg. Chem. 1995, 43, 409. (d) Ayers, W. M. Ed. Catalytic Activation of Carbon Dioxide, ACS Symposium Series 363, Washington, DC 1988. (e)... 

Equations 1 to 3 show some of fixation reactions of carbon dioxide. Equations la and lb present coupling reactions of CO2 with diene, triene, and alkyne affording lactone and similar molecules [2], in a process catalyzed by low valent transition metal compounds such as nickel(O) and palladium(O) complexes. Another interesting CO2 fixation reaction is copolymerization of CO2 and epoxide yielding polycarbonate (equation 2). This reaction is catalyzed by aluminum porphyrin and zinc diphenoxide [3],... 

In the field of olefin carboxylation, stoichiometric reactions have been described to occur between non-activated alkenes, CO2 and an electron-rich transition-metal complexes, such as Ni(0) [3], Ti(II) [4] or Fe(0) [5]. A Pd-catalyzed CO2 fixation occurs into methylenecyclopropane derivatives affording lactones [6]. The reaction of carbon dioxide with ethylene is difficult and its carboxylation to propionic acid, catalyzed by Rh derivatives [7], needs drastic experimental conditions. 

Also, I wish to mention the catalytic reaction which proceeds via metathesis with heterolytic o-bond activation. Hydrogenation of carbon dioxide to formic acid is one of attractive transition-metal catalyzed CO2 fixation reactions. Rh(I), Rh(III), and Ru(II) complexes were used as a catalyst [54-56]. Of those catalysts, the Ru(II)-catalyzed hydrogenation of CO2 has drawn considerable interest because of its very high efficiency. Its catalytic cycle was theoretically investigated [57]. In this catalytic reaction, the first step is the insertion of CO2 into the Ru-H bond, to afford the ruthenium(II) formate complex, RuHIir -OCOHKPHjIj,... 

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