Recent advances in the catalytic fixation of carbon dioxide to value-added chemicals over alkali metal salts

Diethylene Glycol/NaBr Catalyzed CO2 Insertion into Terminal Epoxides: From Batch to Continuous Flow

“…Albeit thermodynamically disfavored, this last sequence (addition/dehydration) has been described under a range of different conditions. [29] A similar outcome was observed when performing CF CO 2 insertion reactions on epoxide 1 e: increasing coil length resulted in a quantitative conversion with an excellent selectivity to the F L = 0.1 mL • min À 1 , F CO2 = 1 mL • min À 1 , p = 120 bar, T = 220°C. Run 0 (first reaction) refers to the result of Entry 5, Table 3.…”

“…The catalytic system was then further optimized using PEG400 dimethyl ether as a complexing agent, allowing a scaling up of the CO 2 insertion reaction starting from 10 g of reacting epoxides. [25][26][27][28][29] In the light of these results, as a part of our long standing interest in sustainable CF reactions, [30][31][32][33] we were prompted to investigate whether mixtures of organic ligands based on oligo-and poly-glycols and alkali/alkaline earth metal halides, could be used for the preparation of COCs in CF mode. This was a substantially unexplored area with major challenges associated to the control of the viscosity of the complexing agent and the design of a liquid/gas biphasic system able to ensure reactants/catalyst miscibility and suitable contact time for the process.…”

The role of Zn in the sustainable one-pot synthesis of dimethyl carbonate from carbon dioxide, methanol and propylene oxide

“…MgO has also been employed by De and co-workers in combination with a supported basic ionic liquid-choline hydroxide (De et al, 2009). A review of the role of alkali metal salts in catalytic carbon dioxide utilisation is provided by Truong and Mishra (Truong and Mishra, 2020). Li et al, 2015) KOH--zeolite 20 23.3% - (Xu et al, 2013) This work therefore considers the application of ZnO-supported NaBr (as an alkali halide) promoted with K 2 CO 3 (as a strong base) in the synthesis of DMC from CO 2 , methanol and PO at 160 C and 20 bar over a reaction time of 5 hours.…”

Advances in Palladium-Catalyzed Carboxylation Reactions

“…In fact, it allows converting an important waste (it is well known that carbon dioxide is produced in enormous amounts from the combustion of fossil fuels for the production of energy) into a variety of useful compounds, which can find application as fuels or in the pharmaceutical or material fields. Accordingly, many efforts have been devoted by the scientific community to develop novel efficient and sustainable carboxylation methods, in particular under catalytic conditions, during the last years [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ].…”