36368-40-8Relevant academic research and scientific papers
Aluminum-Mediated Formation of Cyclic Carbonates: Benchmarking Catalytic Performance Metrics
Rintjema, Jeroen,Kleij, Arjan W.
, p. 1274 - 1282 (2017)
We report a comparative study on the activity of a series of fifteen binary catalysts derived from various reported aluminum-based complexes. A benchmarking of their initial rates in the coupling of various terminal and internal epoxides in the presence of three different nucleophilic additives was carried out, providing for the first time a useful comparison of activity metrics in the area of cyclic organic carbonate formation. These investigations provide a useful framework for how to realistically valorize relative reactivities and which features are important when considering the ideal operational window of each binary catalyst system.
Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide by Using Bifunctional One-Component Phosphorus-Based Organocatalysts
Büttner, Hendrik,Steinbauer, Johannes,Werner, Thomas
, p. 2655 - 2669 (2015/09/02)
Numerous bifunctional organocatalysts were synthesized and tested for the atom-efficient addition of carbon dioxide and epoxides to produce cyclic carbonates. These catalysts are based on phosphonium salts containing an alcohol moiety in the side chain for substrate activation through hydrogen bonding. In the model reaction, converting 1,2-butylene oxide with CO2, 19 catalysts were tested to determine structure-activity relationships. In total, 28 epoxides were converted with CO2 to give the respective cyclic carbonates in yields of up to 99%. Even at 45C, the most active catalyst was able to produce cyclic carbonates selectively in high yields. The carbonates were generally obtained as analytically pure products after simple filtration over silica gel. This single-component catalyst system works under neat and mild reaction conditions and tolerates several useful moieties. Two heads are better than one! Bifunctional organocatalysts are synthesized and tested in the catalytic reaction of epoxides and carbon dioxide to give the respective cyclic carbonates. Product formation is significantly increased by hydrogen-bond donation from the bifunctional phosphonium catalyst.
Cyclocondensation of oxalyl chloride with 1,2-glycols
Iida,Itaya
, p. 10511 - 10530 (2007/10/02)
Oxalyl chloride reacts with a wide range of acyclic 1,2-glycols 1 in the presence of triethylamine to produce 1,3-dioxolan-2-ones 3 together with 1,4-dioxane-2,3-diones 2. Ethylene glycol (1d), monosubstituted ethylene glycols 1e, j-l, and erythro-1,2-disubstituted ethylene glycols 1f, m, o provide the cyclic carbonates 3 as the minor products, while the threo-compounds 1g, i, n, p, q and pinacol (1h) afford 3 as the main products. The formation of 3 may be rationalized in terms of stereoelectronically controlled cleavage of the conjugate base 17- of the tetrahedral intermediates. The rate of the conformational change of 17- into 18- and the equilibrium constant between these conformers are proposed to be the major factors affecting the reaction pattern.
