scholarly journals Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide

2018 ◽  
Vol 14 ◽  
pp. 2348-2353 ◽  
Author(s):  
Lu Yang ◽  
Yuwei Wu ◽  
Yiming Yang ◽  
Chengping Wen ◽  
Jie-Ping Wan
Keyword(s):  
High Efficiency ◽  
Cycloaddition Reactions ◽  
Mild Conditions ◽  
Catalyst Free

The synthesis of 4-acyl-NH-1,2,3-triazoles has been accomplished with high efficiency through the cycloaddition reactions between N,N-dimethylenaminones and tosyl azide. This method is featured with extraordinary sustainability by employing water as the sole medium, free of any catalyst or additive, authentically mild conditions (40 °C stirring) as well as practical scalability.

Application of Poly(Vinylbenzyltrimethylammonium Tribromide) Resin as an Efficient Polymeric Catalyst in the Acetalization and Diacetylation of Benzaldehydes

2020 ◽  
Vol 17 ◽  
Author(s):  
Zubiao Zheng ◽  
Bingbing Han ◽  
Junjun Hu ◽  
Xianwei Li
Keyword(s):  
High Efficiency ◽  
Optimal Conditions ◽  
Mild Conditions ◽  
Polymeric Catalyst

: The applications of a new supported tribromide reagent (poly(vinylbenzyltrimethylammonium tribromide) resin) were reported. This supported tribromide resin was used as a catalyst in the acetalization and diacetylation of benzaldehydes under mild conditions with high efficiency. The effects of solvents, amount of the supported tribromide resin on the reactions were investigated. Under the optimal conditions, most of acetal and 1,1-diacetates of benzaldehydes were selectively obtained in excellent yields.

scholarly journals Hydrogenation of benzoic acid derivatives over Pt/TiO2 under mild conditions

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Miao Guo ◽  
Xiangtao Kong ◽  
Chunzhi Li ◽  
Qihua Yang
Keyword(s):  
Electron Transfer ◽  
Benzoic Acid ◽  
High Efficiency ◽  
Carboxyl Groups ◽  
Carboxyl Group ◽  
Benzoic Acids ◽  
Catalyst Poisoning ◽  
Benzoic Acid Derivatives ◽  
Mild Conditions ◽  
Transfer Direction

AbstractHydrogenation of benzoic acid (BA) to cyclohexanecarboxylic acid (CCA) has important industrial and academic significance, however, the electron deficient aromatic ring and catalyst poisoning by carboxyl groups make BA hydrogenation a challenging transformation. Herein, we report that Pt/TiO2 is very effective for BA hydrogenation with, to our knowledge, a record TOF of 4490 h−1 at 80 °C and 50 bar H2, one order higher than previously reported results. Pt/TiO2 catalysts with electron-deficient and electron-enriched Pt sites are obtained by modifying the electron transfer direction between Pt and TiO2. Electron-deficient Pt sites interact with BA more strongly than electron-rich Pt sites, helping the dissociated H of the carboxyl group to participate in BA hydrogenation, thus enhancing its activity. The wide substrate scope, including bi- and tri-benzoic acids, further demonstrates the high efficiency of Pt/TiO2 for hydrogenation of BA derivatives.

Unprecedentedly high efficiency for photocatalytic conversion of methane to methanol over Au–Pd/TiO2 – what is the role of each component in the system?

2021 ◽  
Author(s):  
Xiaojiao Cai ◽  
Siyuan Fang ◽  
Yun Hang Hu
Keyword(s):  
Methane Conversion ◽  
High Efficiency ◽  
Mild Conditions ◽  
Highly Efficient ◽  
System P ◽  
Conversion Of Methane

Direct and highly efficient methane conversion to methanol under mild conditions is achieved via photocatalysis over Au–Pd/TiO2.

Continuous flow processes for the S-alkynylation of cysteine-containing peptides and thioglycoside under catalyst-free, oxidant-free and mild conditions

2021 ◽  
Author(s):  
Long-Zhou Qin ◽  
Xin Yuan ◽  
Jie Liu ◽  
Meng-yu Wu ◽  
Qi Sun ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Mild Conditions ◽  
Catalyst Free ◽  
Flow Processes ◽  
Novel Method

Herein, we develop a novel method for the selective alkynylation of cysteine-containing peptides and 1-thioglycoside residues by the use of continuous flow. This method was characterised by the mild conditions...

scholarly journals Silica Nanoflowers-Stabilized Pickering Emulsion as a Robust Biocatalysis Platform for Enzymatic Production of Biodiesel

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1026 ◽  
Author(s):  
Lihui Wang ◽  
Xinlong Liu ◽  
Yanjun Jiang ◽  
Peng Liu ◽  
Liya Zhou ◽  
...  
Keyword(s):  
High Efficiency ◽  
Pickering Emulsion ◽  
Biodiesel Production ◽  
Candida Antarctica Lipase ◽  
Waste Oil ◽  
Enzymatic Production ◽  
Mild Conditions ◽  
Experimental Yield ◽  
Optimized Conditions ◽  
Better Than

Enzymatic production of biodiesel had attracted much attention due to its high efficiency, mild conditions and environmental protection. However, the high cost of enzyme, poor solubility of methanol in oil and adsorption of glycerol onto the enzyme limited the popularization of the process. To address these problems, we developed a silica nanoflowers-stabilized Pickering emulsion as a biocatalysis platform with Candida antarctica lipase B (CALB) as model lipase for biodiesel production. Silica nanoflowers (SNFs) were synthesized in microemulsion and served as a carrier for CALB immobilization and then used as an emulsifier for constructing Pickering emulsion. The structure of SNFs and the biocatalytic Pickering emulsion (CALB@SNFs-PE) were characterized in detail. Experimental data about the methanolysis of waste oil to biodiesel was evaluated by response surface methodology. The highest experimental yield of 98.5 ± 0.5% was obtained under the optimized conditions: methanol/oil ratio of 2.63:1, a temperature of 45.97 °C, CALB@SNFs dosage of 33.24 mg and time of 8.11 h, which was closed to the predicted value (100.00%). Reusability test showed that CALB@SNFs-PE could retain 76.68% of its initial biodiesel yield after 15 cycles, which was better than that of free CALB and N435.

Nickel-Catalyzed Reductive Monofluoroakylation of Alkyl Tosylate with Bromofluoromethane to Access Primary Alkyl Fluoride

2021 ◽  
Author(s):  
Ru Cui ◽  
Jie Sheng ◽  
Bing-Bing Wu ◽  
Duo-Duo Hu ◽  
Hong-Qian Zheng ◽  
...  
Keyword(s):  
Functional Group ◽  
High Efficiency ◽  
Low Cost ◽  
Raw Material ◽  
Mild Conditions

A nickel-catalysed direct terminal monofluormethlyation between alkyl tosylates and a low-cost, industrial raw material bromofluoromethane has been developed. This transformation has demonstrated high efficiency, mild conditions, and good functional-group compatibility....

scholarly journals Nickel-catalyzed deaminative Sonogashira coupling of alkylpyridinium salts enabled by NN2 pincer ligand

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xingjie Zhang ◽  
Di Qi ◽  
Chenchen Jiao ◽  
Xiaopan Liu ◽  
Guisheng Zhang
Keyword(s):  
Functional Group ◽  
High Efficiency ◽  
Materials Science ◽  
Alkylating Agents ◽  
Sonogashira Coupling ◽  
Pincer Ligand ◽  
One Pot ◽  
Mild Conditions ◽  
Alkyl Amines ◽  
Sonogashira Reactions

AbstractAlkynes are amongst the most valuable functional groups in organic chemistry and widely used in chemical biology, pharmacy, and materials science. However, the preparation of alkyl-substituted alkynes still remains elusive. Here, we show a nickel-catalyzed deaminative Sonogashira coupling of alkylpyridinium salts. Key to the success of this coupling is the development of an easily accessible and bench-stable amide-type pincer ligand. This ligand allows naturally abundant alkyl amines as alkylating agents in Sonogashira reactions, and produces diverse alkynes in excellent yields under mild conditions. Salient merits of this chemistry include broad substrate scope and functional group tolerance, gram-scale synthesis, one-pot transformation, versatile late-stage derivatizations as well as the use of inexpensive pre-catalyst and readily available substrates. The high efficiency and strong practicability bode well for the widespread applications of this strategy in constructing functional molecules, materials, and fine chemicals.

Cobalt-catalyzed carboxylation of aryl and vinyl chlorides with CO2

2020 ◽  
Vol 56 (92) ◽  
pp. 14416-14419
Author(s):  
Yanwei Wang ◽  
Xiaomei Jiang ◽  
Baiquan Wang
Keyword(s):  
High Efficiency ◽  
Mild Conditions

Cobalt-catalyzed carboxylation of aryl and vinyl chlorides and bromides with CO2 has been developed. These transformations proceed under mild conditions and exhibit a broad substrate scope and high efficiency.

From Furan–Yne Systems to para-Benzoquinone Derivatives: Gold-Catalyzed Cyclization and Oxidation, and Further Reduction by Sodium Dithionate

Synthesis ◽  
2020 ◽  
Author(s):  
Mohammad Ghanbari ◽  
Saman Ahmadi
Keyword(s):  
High Efficiency ◽  
One Pot ◽  
Subsequent Oxidation ◽  
Mild Conditions ◽  
Phenol Synthesis ◽  
Step Procedure

AbstractA series of furan–yne systems were transformed into the corresponding para-benzoquinone derivatives by gold(ΙΙΙ) catalyst. The two-step procedure consisted of a phenol synthesis and subsequent oxidation with iodobenzene diacetate. The reactions can be carried out in a one-pot procedure with the same precatalyst. The para-benzoquinone could simply be converted into the corresponding hydroquinones by reduction with sodium dithionate. This protocol features high efficiency, mild conditions, and wide substrate scopes.

Anhydrous Conditions Enable the Catalyst‐Free Carboxylation of Aromatic Alkynes with CO 2 under Mild Conditions

2020 ◽  
Vol 103 (2) ◽  
Author(s):  
Davide Toniolo ◽  
Felix D. Bobbink ◽  
Paul J. Dyson ◽  
Marinella Mazzanti
Keyword(s):  
Mild Conditions ◽  
Catalyst Free
Sign in / Sign up

Export Citation Format

Share Document