- Zeolite-catalyzed acetalization reaction of furfural with alcohol under solvent-free conditions
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Acetalization reactions present a viable method for producing valuable chemicals and protecting carbonyl functionalities in organic compounds. Herein, several commercial zeolites were used as solid acid catalysts in the acetalization of biomass-derived furfural with alcohols under solvent-free conditions. The effects of major reaction parameters such as catalyst concentration, reaction temperature, and reaction time were investigated. Among the tested catalysts, SAPO-34 with appropriate acid sites and textural structure exhibited the highest catalytic activity under optimized reaction conditions. Additionally, the catalyst showed excellent recyclability and no obvious deactivation was observed even after using it six times.
- Jin, Fuxiang,Liu, Hailong,Liu, Qiao,Song, Heyuan
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- Aldehyde group protection method of biomass-based furan compound
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The invention discloses an aldehyde group protection method of a biomass-based furan compound. The aldehyde group protection method comprises the following steps: under the action of an acidic catalyst, the aldehyde group-containing biomass-based furan compound reacts with an aldehyde group protection reagent to generate an acetal compound. The acidic catalyst is selected from pKa acids having -12 of 3 and Bronsted. The aldehyde group protecting reagent is selected from mono- di-or even polyhydric alcohol compounds. The efficient separation and purification step is simple in operation, and the gram level can be easily realized without the column chromatography separation method of the traditional time-consuming solvent. Of purity acetals products. The catalyst is low in price and simple and feasible in purification method, and can be used for efficiently and large-scale preparation of the biomass-based furan acetal compound for later-stage derivatization reaction.
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Paragraph 0037; 0041; 0054-0091
(2021/10/20)
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- Direct anodic (thio)acetalization of aldehydes with alcohols (thiols) under neutral conditions, and computational insight into the electrochemical formation of the acetals
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A versatile protocol for the production of acetals/thioacetals by means of direct electrochemical oxidation is developed here under neutral conditions, providing (thio)acetals with good functional group tolerance and a wide scope for both aldehydes and (thio)alcohols. DFT calculations reveal that direct electron transfer from the anode plays a key role in carbonyl activation during this acid free acetalization process.
- Liu, Caiyan,Shen, Yongli,Xiao, Zihui,Yang, Hui,Han, Xue,Yuan, Kedong,Ding, Yi
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p. 4030 - 4034
(2019/08/07)
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- PRODUCTION METHOD OF CARBOXYLIC ACID ESTER OR CARBOXYLIC ACID
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PROBLEM TO BE SOLVED: To provide a production method of carboxylic acid ester or carboxylic acid, which can obtain carboxylic acid ester or carboxylic acid that is a target at a high yield while suppressing a side reaction and has excellent long term operation stability when producing the carboxylic acid ester or carboxylic acid having a furan skeleton derived from a biomass raw material. SOLUTION: When producing a carboxylic acid ester or carboxylic acid having a furan skeleton derived from a biomass raw material, a production method of the carboxylic acid ester or carboxylic acid via a cyclic acetal intermediate is provided. The carboxylic acid ester or carboxylic acid having a furan skeleton is produced by producing the cyclic acetal intermediate and by undergoing its oxidation reaction step. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2018,JPO&INPIT
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Paragraph 0137
(2018/05/26)
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- PRODUCTION METHOD OF ALCOHOL
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PROBLEM TO BE SOLVED: To provide a production method of alcohol, which can obtain alcohol that is a target at a high yield while suppressing a side reaction and has long term operation stability when producing alcohol from a biomass raw material. SOLUTION: When producing alcohol from a biomass raw material, a method in which alcohol is produced via an acetal intermediate having a furan skeleton is provided. Alcohol is produced by producing an acetal intermediate and by undergoing a step of hydrogenating this with hydrogen gas. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0136; 0141
(2018/05/26)
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- Acetalization of carbonyl compounds catalyzed by bismuth triflate under solvent-free conditions
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Carbonyl compounds were converted to the corresponding 1,3-dioxolanes and 1,3-dioxanes with ethylene glycol and 1,3-propandiol in the presence of bismuth triflate under solvent-free conditions. In addition, high chemoselective protection of aldehydes in the presence of ketones has been achieved.
- Aliyan, Hamid,Fazaeli, Razieh,Massah, Ahmad Reza,Momeni, Ahmad Reza,Naghash, Hamid Javaherian,Moeinifard, Behzad
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experimental part
p. 873 - 876
(2012/04/05)
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- N-bromosuccinimide (NBS) catalyzed highly chemoselective acetalization of carbonyl compounds using silylated diols and pentaerythritol under neutral aprotic conditions
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Various types of carbonyl compounds are efficiently converted to their 1,3-dioxanes and pentaerythritol diacetals by the use of either 1,3-bistrimethylsiloxy propane (A) or 1,3-bistrimethylsilanyloxy-2,2- bistrimethylsilanyloxymethyl propane (D) and a catalytic amount of N-bromosuccinimide (3-10 mol%) under essentially neutral aprotic condition, respectively. A variety of functionalities such as both aliphatic and phenolic -OTBDMS, -OMe, -OBz, furan ring, double bonds and more significantly phenolic -OTHP survived under the present reaction condition. The efficient conversion of two α-tertiary ketones to their cyclic acetals was also achieved using the present protocol.
- Karimi, Babak,Hazarkhani, Hassan,Maleki, Jafar
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p. 279 - 285
(2007/10/03)
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- A convenient and highly efficient method for the protection of aldehydes using very low loading hydrous ruthenium(III) trichloride as catalyst
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A convenient method for the chemoselective protections of both aliphatic and aromatic aldehydes has been developed. Ruthenium(III) trichloride (0.1 mol %) has found to be an highly efficient catalyst in the acetalizations of aldehydes with various simple alcohols such as methanol, ethanol, or diols such as 1,2-ethylanediol and 1,3-propanediol under mild reaction conditions.
- Qi, Jian-Ying,Ji, Jian-Xin,Yueng, Chi-Hung,Kwong, Hoi-Lun,Chan, Albert S.C.
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p. 7719 - 7721
(2007/10/03)
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- Tetrabutylammonium tribromide (TBATB) as an efficient generator of HBr for an efficient chemoselective reagent for acetalization of carbonyl compounds
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Acyclic and cyclic acetals of various carbonyl compounds were obtained in excellent yields under a mild reaction condition in the presence of trialkyl orthoformate and a catalytic amount of tetrabutylammonium tribromide (TBATB) in absolute alcohol. Chemoselective acetalization of an aldehyde in the presence of ketone, unsymmetrical acetal formation, shorter reaction times, mild reaction conditions, the stability of acid-sensitive protecting groups, high efficiencies, facile isolation of the desired products, and the catalytic nature of the reagent make the present methodology a practical alternative.
- Gopinath, Rangam,Haque, Sk. Jiaul,Patel, Bhisma K.
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p. 5842 - 5845
(2007/10/03)
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- Iodine-catalyzed, efficient and mild procedure for highly chemoselective acetalization of carbonyl compounds under neutral aprotic conditions
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Various types of carbonyl compounds are efficiently converted to their 1,3-dioxanes by the use of 1,3-bis(trimethylsiloxy)propane (BTSP) and a catalytic amount of iodine (3-7 mol%) under essentially neutral aprotic condition.
- Karimi, Babak,Golshani, Behzad
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p. 784 - 788
(2007/10/03)
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- Synthesis and structure analysis of cyclic furfural acetals
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Quantum chemical calculations and the PMR method are used to show that the preferable conformation of cyclic furfural acetals is a chair with an axial orientation of the furyl substituent. In 2-(furyl-2′)-5-ethyl-5-oxymethyl-1,3-dioxane, the conformation equilibrium is shifted toward the trans-isomer with diaxial positions of the furyl and oxymethyl groups. The results of calculations suggest that the synthesis can lead to a cis-isomer with an axial orientation of the furyl and equatorial oxymethyl groups. It was shown experimentally that the synthesis leads to a mixture of trans- and cis-isomers. Mild conditions (room temperature, aqueous medium) lead to formation of the trans-isomer and small amounts of the cis-isomer (less than 2%). In rigid conditions (boiling in aromatic hydrocarbons), up to 20% of the cis-isomer is formed. 1998 Plenum Publishing Corporation.
- Melnitskaya,Kuramshin,Khlebnikova,Melnitskii,Kantor
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p. 908 - 914
(2007/10/03)
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