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"Introduction:
Development of green processes based on chemical fixation of carbon dioxide (CO2) has received a great deal of interest in recent years because carbon dioxide could be used as a safe and cheap C1 building block to produce useful organic compounds.1 A large number of studies have been devoted to the fixation of CO2 for synthesis of alkylidene carbonates, which are usually obtained from reactions between CO2 and propargylic alcohols catalyzed over various metal complexes2 including Cu, Co, Ru, and Pd or in the presence of large amounts of tertiary phosphines,3 because the five-membered ring alkylidene carbonates are important intermediates for many organic syntheses.4 However, the use of tertiary amines, large amounts of organic solvents, and high CO2 pressure (ca. 5.0 MPa) was unavoidable in order to achieve good results. Additionally, this reaction usually proceeded in volatile organic solvents, such as DMF or THF. Therefore, it is necessary to develop a mild, clean, and efficient method for the synthesis of alkylidene carbonates from carbon dioxide. Room temperature ionic liquids, especially those based on the 1-alkyl-3-methylimidazolium cations, have shown great promise as an attractive alternative to conventional organic solvents, and much attention has been currently focused on organic reactions promoted by ionic liquids..."
From the Journal of Organic Chemistry, (J. Org. Chem.; (Article); 2004; 69(2); 391-394.)
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