2453-03-4Relevant articles and documents
Mechanochemical synthesis of poly(trimethylene carbonate)s: An example of rate acceleration
Park, Sora,Kim, Jeung Gon
, p. 963 - 970 (2019)
Mechanochemical polymerization is a rapidly growing area and a number of polymeric materials can now be obtained through green mechanochemical synthesis. In addition to the general merits of mechanochemistry, such as being solvent-free and resulting in high conversions, we herein explore rate acceleration under ball-milling conditions while the conventional solution-state synthesis suffer from low reactivity. The solvent-free mechanochemical polymerization of trimethylene carbonate using the organocatalysts 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) are examined herein. The polymerizations under ball-milling conditions exhibited significant rate enhancements compared to polymerizations in solution. A number of milling parameters were evaluated for the ball-milling polymerization. Temperature increases due to ball collisions and exothermic energy output did not affect the polymerization rate significantly and the initial mixing speed was important for chain-length control. Liquid-assisted grinding was applied for the synthesis of high molecular weight polymers, but it failed to protect the polymer chain from mechanical degradation.
Experimental Evidence for the Stereoelectronically Controlled Hydrolysis of Orthocarbonates
Li, Shigui,Deslongchamps, Pierre
, p. 5641 - 5644 (1994)
The acid hydrolysis of cyclic and acyclic orthoesters 1-6 is reported.The results obtained are explained by taking into account the principle of stereoelectronic control.
Preparation and characterization of polyester- and poly(ester-carbonate)- paclitaxel conjugates
Sobczak, Marcin,Korzeniowska, Agnieszka,Go?, Piotr,Kolodziejski, Waclaw L.
, p. 3047 - 3051 (2011)
The polyester- and poly(ester-carbonate)-paclitaxel conjugates with low molecular weight were synthesized using dicyclohexylcarbodiimide (DCC) and dimethylaminopyridine (DMAP) as catalysts. Polymeric matrices were obtained by ring-opening polymerization of ε-caprolactone (CL), rac-lactide (rac-LA), l-lactide (LLA) and trimethylene carbonate (TMC). The macromolecular conjugates were characterized by using spectroscopic techniques, such as 1H, 13C NMR and FTIR. The degree of degradation of polyester- and poly(ester-carbonate)-paclitaxel conjugates was tested in vitro under different conditions. The preliminary results of drug release were discussed.
CYCLOADDITION OF OXETANE AND CARBON DIOXIDE CATALYZED BY TETRAPHENYLSTIBONIUM IODIDE
Baba, Akio,Kashiwagi, Hiroki,Matsuda, Haruo
, p. 1323 - 1324 (1985)
Trimethylene carbonate was readily obtained in the reaction of oxetane and carbon dioxide in the presence of tetraphenylstibonium iodide.
Selective formation of trimethylene carbonate (TMC): Atmospheric pressure Carbon dioxide utilization
Buckley, Benjamin R.,Patel, Anish P.,Wijayantha, K.G. Upul
, p. 474 - 478 (2015)
Carbon dioxide utilisation (CDU) is currently gaining increased interest due to the abundance of CO2 and its possible application as a C1 building block. We herein report the first example of atmospheric pressure carbon dioxide incorporation into oxetane to selectively form trimethylene carbonate (TMC), which is a significant challenge as TMC is thermodynamically less favoured than its corresponding co-polymer.
Ultrasound-assisted synthesis of a stable Co(II) coordination polymer as heterogeneous catalyst for CO2 transformation
Liu, Ce,Liu, Lin,Han, Zheng-Bo
, (2021)
A stable benzimidazole-containing Co(II) coordination polymer namely [Co(L)0.5(oba)]n (1) (H2oba = 4,4′-oxybis(benzoate), L = 1,6-bis(5,6-dimethylbenzimidazolyl) hexane) was successfully synthesized by ultrasonic technique under mild conditions. In especial, the effects of initial reagent concentration, irradiation time and ultrasonic power on the morphology and size of micron scale 1 were discussed in detail. Micron scale 1 appeared exceptional solvent and pH stabilities. Further, as a heterogeneous Lewis catalyst, 1 exhibited a highly activity and recyclability for CO2 transformation by cycloaddition with epoxide under room temperature.
PROCESS FOR THE SYNTHESIS OF ISOCYANATE-FREE OMEGA-HYDROXY-URETHANES, ALPHA-OMEGA-DIURETHANES AND OLIGO (POLY)URETHANES
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Page/Page column 6-7, (2021/11/26)
The synthesis of omega-hydroxyalkyl-urethanes, and of alfa-omega-diurethanes is reported which includes the reaction of diols with urea in presence of catalysts based on Ce at temperatures between 125 and 170°C over 4-8 h reaction time. A process for the production of oligomers of omega-hydroxyalkyl-urethanes is also reported based on the reaction of urea with diols in presence of Ce or Zr catalysts or Ce mixed oxides at 125-170°C over 4-20 h.
Rational Design of Cobalt Complexes Based on the trans Effect of Hybrid Ligands and Evaluation of their Catalytic Activity in the Cycloaddition of Carbon Dioxide with Epoxide
Bu, Qingqing,Dai, Bin,Liu, Ning,Liu, Qiuli,Song, Wen-Yue,Wei, Donghui
, p. 3546 - 3561 (2020/11/02)
A series of cobalt complexes are presented as effective catalysts for the synthesis of cyclic carbonates from epoxides and CO2. The catalytic potentials of the cobalt complexes, in combination with tetrabutylammonium bromide, have been demonstrated to solve some challenges in the synthesis of cyclic carbonates, including the room-temperature conversion of terminal epoxides and activation-challenging substrates such as internal epoxides and fatty acid derived epoxides. A key factor in the success of the strategy is the use of cobalt complexes that are prepared on the basis of the trans effect of hybrid ligands. The trans effect between N-heterocyclic carbenes and acetylacetone has been proved by a number of spectroscopic measurements, including UV-vis, ESI-MS, EPR, and in situ FT-IR and by DFT calculations; these support the notion that acetylacetone prefers to dissociate from the cobalt center, which will result in one coordination site for the activation of a substrate molecule at the cobalt atom and thus give rise to high reactivity.
