Organic Carbonates as Solvents in Synthesis and Catalysis

Efficient Catalytic System Involving Molybdenyl Acetylacetonate and Immobilized Tributylammonium Chloride for the Direct Synthesis of Cyclic Carbonates from Carbon Dioxide and Olefins

“…Procedure 1 An olefin (58 mmol), MoO 2 (acac) 2 (0.058 mmol), TBHP (64 mmol), PS-TBMAC (0.58 mmol), an aqueous solution of ZnBr 2 (0.80 mmol of H 2 O, 0.16 mmol of ZnBr 2 ), and an internal standard (0.4 g octane, or nonane, depending on the olefin used in the process) were added into an autoclave. The reactor was sealed and purged two times with carbon dioxide.…”

“…Catalyst reusability: After the completion of the reaction, the immobilized catalyst was simply recovered by filtration, washed with dichloromethane (6 × 5 ml). The filtrate was extracted with ethanol (3 × 5 ml) in order to extract MoO 2 (acac) 2 . The separated PS-TBMAC during the filtration was dried in vacuum and then reused for the next run.…”

“…The quaternary ammonium salt with a halogen anion could catalyze the decomposition reaction of tert-butyl hydroperoxide and MoO 2 (acac) 2 , resulting in the formation of oxygen, tert-butanol and MoO 2 Br 2 [15]. Thus, in a further experiment CO 2 , PS-TBMAC and an aqueous solution of ZnBr 2 were added to the reaction system after one hour (procedure 3).…”

“…The highest yield that has been achieved for styrene carbonate was 45%. Sun and co-workers proposed the catalyst system consisting of Au supported on Fe(OH) 3 , ZnBr 2 and TBAB for the synthesis of styrene carbonate using CHP as an oxidant [13]. Under reaction conditions of 80 °C, a CO 2 pressure of 4 MPa, styrene carbonate was obtained in yield of 53% after 10 h. In turn, the use of gold (0.01 wt%) supported on R201 resin functionalized with quaternary ammonium functional groups allowed to obtain styrene carbonate in 51% yield [14].…”

“…The reaction selectivity was 52%. Styrene carbonate can also be obtained in the reaction conducted in the presence of the MoO 2 (acac) 2 , TBAB catalytic system and TBHP as an oxidant [15]. The styrene epoxidation reaction was carried out for 1 h at the temperature of 100 °C.…”