87831-99-0Relevant academic research and scientific papers
Development of a H3PW12O40/CeO2 catalyst for bulk ring-opening polymerization of a cyclic carbonate
Honda, Masayoshi,Abe, Hideki
, p. 4995 - 5006 (2018/11/10)
A new reaction system involving a heterogeneous H3PW12O40/CeO2 catalyst and methyl iodide initiator was developed for bulk ring-opening polymerization (ROP) of trimethylene carbonate (TMC). Combination of a Br?nsted acid (H3PW12O40) and Lewis base (CeO2) had a synergic effect on a well-controlled ROP without decarboxylation, which gave poly(TMC) of molecular weight (Mn) 30-000 and Polydispersity Index (PDI) of 1.80 at 60 °C and 24 h. Fourier transform infrared (FTIR) spectroscopy elucidated a reaction mechanism in which H3PW12O40 promoted the initiation reaction and CeO2 activated TMC, and the interface of these two components was an active site for ROP. The catalyst was removed readily by filtrating a dimethyl carbonate solution of poly(TMC), which was confirmed by inductively coupled plasma-atomic emission spectroscopy. In addition, various kinds of biomass-derived poly(aliphatic carbonate)s were synthesized and thermal properties were investigated by differential scanning calorimetry and thermogravimetry-differential thermal analysis. In particular, pyrolysis-gas chromatography mass spectrometry of these polymers revealed that the degradation mechanism was highly dependent upon a small amount of ether linkages and a pendant methyl group.
Chlorine-Free Synthesis of Organic Alkyl Carbonates and Five- and Six-Membered Cyclic Carbonates
Pyo, Sang-Hyun,Hatti-Kaul, Rajni
supporting information, p. 834 - 839 (2016/03/09)
This report presents a new, one-pot, facile, selective and green method for methoxycarbonylation of alcohols and synthesis of five- and six-membered cyclic carbonates from corresponding alcohols with dimethyl carbonate (DMC) in the presence of molecular sieves without any additional solvent and catalyst. Syntheses of bifunctional structures comprising a six-membered cyclic carbonate with allyl ether and methacrylate groups, respectively, for different polymerization modes, were also achieved and showed reproducibility on up-scaling the processes.
Direct cyclic carbonate synthesis from CO2 and diol over carboxylation/hydration cascade catalyst of CeO2 with 2-cyanopyridine
Honda, Masayoshi,Tamura, Masazumi,Nakao, Kenji,Suzuki, Kimihito,Nakagawa, Yoshinao,Tomishige, Keiichi
, p. 1893 - 1896 (2014/06/24)
We first achieved direct synthesis of propylene carbonate from CO 2 and 1,2-propanediol in excellent yield (>99%) using a carboxylation/hydration cascade catalyst of CeO2 with 2-cyanopyridine. The catalyst system can be applied to syntheses of various cyclic carbonates, including 6-membered ring carbonates that are difficult to synthesize in high yields (62->99%).
A general and expedient synthesis of 5- and 6-membered cyclic carbonates by palladium-catalyzed oxidative carbonylation of 1,2- and 1,3-diols
Gabriele, Bartolo,Mancuso, Raffaella,Salerno, Giuseppe,Veltri, Lucia,Costa, Mirco,Dibenedetto, Angela
experimental part, p. 1778 - 1786 (2012/04/04)
We present a general, practical, and efficient approach to 5- and 6-membered organic carbonates by palladium-catalyzed direct oxidative carbonylation of 1,2- and 1,3-diols, respectively. Reactions were carried out at 100 °C in N,N-dimethylacetamide as the solvent under 20 atm (at 25 °C; 1 atm=101.3 kPa) of a 4:1 v/v CO/air mixture in the presence of 0.5-2 mol % of PdI2 and KI (KI/PdI2 molar ratio=10). Excess dehydrating agent, such as trimethyl orthoacetate, was necessary in several cases to obtain appreciable results. The method could also be applied to the synthesis of a high-value-added glycerol carbonate from glycerol, a readily available raw material. When applied to α-D-glucose, a double carbonylation process took place, with direct formation of α-D-glucofuranose 1,2:5,6-dicarbonate.
A novel and efficient method for the catalytic direct oxidative carbonylation of 1,2- and 1,3-diols to 5-membered and 6-membered cyclic carbonates
Gabriele, Bartolo,Mancuso, Raffaella,Salerno, Giuseppe,Ruffolo, Giuseppe,Costa, Mirco,Dibenedetto, Angela
experimental part, p. 7330 - 7332 (2010/02/28)
In the presence of a PdI2-based catalytic system, 1,2-diols undergo an oxidative carbonylation process to afford 5-membered cyclic carbonates in good to excellent yields (84-94%) and with unprecedented catalytic efficiencies for this kind of reaction (up to ca. 190 mol of product per mol of PdI2). Under similar conditions, 6-membered cyclic carbonates are obtained for the first time through a direct catalytic oxidative carbonylation of 1,3-diols (66-74% yields).
Selective pyrolysis of bifunctional compounds: gas-phase elimination of carbonate-ester functionalities
Al-Azemi, Talal F.,Dib, Hicham H.,Al-Awadi, Nouria A.,El-Dusouqui, Osman M.E.
, p. 4126 - 4134 (2008/09/20)
Compounds containing both carbonate and ester functionalities were synthesized and then subjected to online-GC gas-phase pyrolysis. The carbonate groups were cleaved selectively in all elimination reactions. The end products of the reaction were found to be affected by the nature of the substrate. The presence of hydrogen and carbonyl substituents on the carbon β to the carbonate group resulted in further product decomposition through a concerted six-membered transition state. Results from flash vacuum pyrolysis (FVP) and analysis of the GC data indicate that the cleavage of the carbonate group is fast, and that the slower secondary decomposition reactions are independent of the presence of the carbonate group. Spectroscopic analyses of the products are reported.
The Cycloaddition of Heterocumulenes to Oxetanes in the Presence of Catalytic Amounts of Tetraphenylstibonium Iodide
Fujiwara, Masahiro,Baba, Akio,Matsuda, Haruo
, p. 1659 - 1663 (2007/10/02)
The cycloadditions of carbon dioxide, isocyanates and carbodiimides to oxetanes proceeded in the presence of catalytic amounts of tetraphenylstibonium iodide (1) under mild conditions, affording the corresponding six-membered heterocycles; 1,3-dioxan-2-ones, 1,3-oxazin-2-ones and 1,3-oxazin-2-imines in good yields, respectively.Moreover, the cycloaddition of 2-phenyloxetane proceeded via predominant ring-cleavage at substituted site.
