- Synthesis of a Pyridine–Zinc-Based Porous Organic Polymer for the Co-catalyst-Free Cycloaddition of Epoxides
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The synthesis of solid catalysts for the co-catalyst-free cycloaddition of CO2 has attracted much attention. Herein, we report a hierarchical porous organic polymer, Py-Zn@MA, that is able to catalyze the cycloaddition reaction of epoxides and CO2 without using any additives or co-catalyst to afford turnover frequency (TOF) values as high as 250 and 97 h?1 at 130 °C by using pure and diluted CO2 (simulating flue gas), respectively. These results are superior to those obtained from previously reported heterogeneous co-catalyst-free systems. The high activity of Py-Zn@MA is mainly attributed to its bifunctional nature with ZnBr2 and pyridine activating the epoxide in a cooperative way. Notably, Py-Zn@MA can be easily prepared on a large scale without using any catalyst and the chemicals are cost effective. Moreover, Py-Zn@MA shows good substrate universality for the cycloaddition reactions of epoxides. Our designed porous organic polymer Py-Zn@MA material has the potential to serve as an efficient catalyst for the direct conversion of flue gas with epoxides into value-added cyclic carbonates.
- Li, He,Li, Chunzhi,Chen, Jian,Liu, Lina,Yang, Qihua
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- Synthesis of Cyclic Anhydrides via Ligand-Enabled C–H Carbonylation of Simple Aliphatic Acids
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The development of C(sp3)–H functionalizations of free carboxylic acids has provided a wide range of versatile C?C and C?Y (Y=heteroatom) bond-forming reactions. Additionally, C–H functionalizations have lent themselves to the one-step preparation of a number of valuable synthetic motifs that are often difficult to prepare through conventional methods. Herein, we report a β- or γ-C(sp3)–H carbonylation of free carboxylic acids using Mo(CO)6 as a convenient solid CO source and enabled by a bidentate ligand, leading to convenient syntheses of cyclic anhydrides. Among these, the succinic anhydride products are versatile stepping stones for the mono-selective introduction of various functional groups at the β position of the parent acids by decarboxylative functionalizations, thus providing a divergent strategy to synthesize a myriad of carboxylic acids inaccessible by previous β-C–H activation reactions. The enantioselective carbonylation of free cyclopropanecarboxylic acids has also been achieved using a chiral bidentate thioether ligand.
- Herron, Alastair N.,Yu, Jin-Quan,Zhuang, Zhe
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supporting information
p. 16382 - 16387
(2021/06/23)
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- Succinic anhydrides from epoxides
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Catalysts and methods for the double carbonylation of epoxides are disclosed. Each epoxide molecule reacts with two molecules of carbon monoxide to produce a succinic anhydride. The reaction is facilitated by catalysts combining a Lewis acidic species with a transition metal carbonyl complex. The double carbonylation is achieved in single process by using reaction conditions under which both carbonylation reactions occur without the necessity of isolating or purifying the product of the first carbonylation.
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Page/Page column 24; 25; 26
(2013/07/25)
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- Catalytic double carbonylation of epoxides to succinic anhydrides: Catalyst discovery, reaction scope, and mechanism
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The first catalytic method for the efficient conversion of epoxides to succinic anhydrides via one-pot double carbonylation is reported. This reaction occurs in two stages: first, the epoxide is carbonylated to a β-lactone, and then the β-lactone is subsequently carbonylated to a succinic anhydride. This reaction is made possible by the bimetallic catalyst [(CITPP)Al(THF)2]+[Co(CO)4]- (1; CITPP = meso-tetra(4-chlorophenyl)porphyrinato; THF = tetrahydrofuran), which is highly active and selective for both epoxide and lactone carbonylation, and by the identification of a solvent that facilitates both stages. The catalysis is compatible with substituted epoxides having aliphatic, aromatic, alkene, ether, ester, alcohol, nitrile, and amide functional groups. Disubstituted and enantiomerically pure anhydrides are synthesized from epoxides with excellent retention of stereochemical purity. The mechanism of epoxide double carbonylation with 1 was investigated by in situ IR spectroscopy, which reveals that the two carbonylation stages are sequential and non-overlapping, such that epoxide carbonylation goes to completion before any of the intermediate β-lactone is consumed. The rates of both epoxide and lactone carbonylation are independent of carbon monoxide pressure and are first-order in the concentration of 1. The stages differ in that the rate of epoxide carbonylation is independent of substrate concentration and first-order in donor solvent, whereas the rate of lactone carbonylation is first-order in lactone and inversely dependent on the concentration of donor solvent. The opposite solvent effects and substrate order for these two stages are rationalized in terms of different resting states and rate-determining steps for each carbonylation reaction.
- Rowley, John M.,Lobkovsky, Emil B.,Coates, Geoffrey W.
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p. 4948 - 4960
(2008/02/03)
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- Synthesis of monosubstituted succinic acids from tert-butylsuccinate
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We report the preparation and alkylation of the dianion of t-butylsuccinate. This alkylation reaction has proven to be a useful method for the preparation of monosubstituted succinic acids and anhydrides.
- Bergmeier,Ismail
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p. 1369 - 1371
(2007/10/03)
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- A new regioselective synthesis of 3-substituted furan-2(5H)-ones by palladium-catalysed reductive carbonylation of alk-1-ynes
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3-Alkyl- or 3-aryl-substituted furan-2(5H)-ones are obtained directly in fair yields by reductive carbonylation of alk-1-ynes in the presence of catalytic amounts of palladium iodide in conjunction with potassium iodide (10 eq.) and water (200 eq.). Simultaneous oxidation of CO to CO2 accounts for the stoichiometry of the process. Reactions are carried out in dioxane under mild conditions (80 °C and 10 atm of carbon monoxide).
- Gabriele, Bartolo,Salerno, Giuseppe,Costa, Mirco,Chiusoli, Gian Paolo
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p. 989 - 990
(2007/10/03)
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- Ashless additives for lubricating compositions
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Superior ashless additives for lubricants are prepared by a process comprising first introducing a petroleum sulfonic acid and a polyamine to a reaction zone and subsequently introducing a cyclic anhydride of a dicarboxylic acid into the reaction zone. In another embodiment, the solids content of the additives is reduced to acceptable levels by removal of free SO2 from the petroleum sulfonic acid prior to preparing the additive. Lubricating oil compositions containing these ashless additives are also provided.
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