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.

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.

Efficient Synthesis of Diverse 5-Thio- or 5-Selenotriazoles: One-Pot Multicomponent Reaction from Elemental Sulfur or Selenium

Synthesis ◽  
2019 ◽  
Vol 51 (22) ◽  
pp. 4170-4182 ◽  
Author(s):  
Lin-Lin Zhang ◽  
Ya-Ting Li ◽  
Ting Gao ◽  
Sha-Sha Guo ◽  
Bei Yang ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Functional Group ◽  
High Efficiency ◽  
Efficient Synthesis ◽  
One Pot ◽  
Mild Conditions ◽  
Ligand Free ◽  
Multistep Reaction ◽  
Easy Operation

A sequential multistep reaction toward 5-thio- or 5-selenotriazoles has been established by generation of both copper(I) triazolides and sulfenylating or selenylating agents in situ, starting from elemental sulfur or selenium. This reaction features mild conditions, readily available and broad-scope substrates, good functional group compatibility, high efficiency and regioselectivity, easy operation, and ligand-free CuI.

Chlorosulfonic Acid Supported Piperidine-4-carboxylic Acid (PPCA) Functionalized Fe3O4 Nanoparticles (Fe3O4-PPCA): The Efficient, Green and Reusable Nanocatalyst for the Synthesis of Pyrazolyl Coumarin Derivatives under Solvent-Free Conditions

2019 ◽  
Vol 22 (2) ◽  
pp. 123-128
Author(s):  
Setareh Habibzadeh ◽  
Hassan Ghasemnejad-Bosra ◽  
Mina Haghdadi ◽  
Soheila Heydari-Parastar
Keyword(s):  
Carboxylic Acid ◽  
Fe3o4 Nanoparticles ◽  
High Efficiency ◽  
Reaction Times ◽  
Chlorosulfonic Acid ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Magnetic Nanocatalyst ◽  
One Pot ◽  
Solvent Free Conditions

Background: In this study, we developed a convenient methodology for the synthesis of coumarin linked to pyrazolines and pyrano [2,3-h] coumarins linked to 3-(1,5-diphenyl-4,5- dihydro-1H-pyrazol-3-yl)-chromen-2-one derivatives using Chlorosulfonic acid supported Piperidine-4-carboxylic acid (PPCA) functionalized Fe3O4 nanoparticles (Fe3O4-PPCA) catalyst. Materials and Methods:: Fe3O4-PPCA was investigated as an efficient and magnetically recoverable Nanocatalyst for the one-pot synthesis of substituted coumarins from the reaction of coumarin with a variety of aromatic aldehydes in high to excellent yield at room temperature under solvent-free conditions. The magnetic nanocatalyst can be easily recovered by applying an external magnet device and reused for at least 10 reaction runs without considerable loss of reactivity. Results and Conclusion: The advantages of this protocol are the use of commercially available materials, simple and an inexpensive procedure, easy separation, and an eco-friendly procedure, and it shows good reaction times, good to high yields, inexpensive and practicability procedure, and high efficiency.

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.

Fast and high-efficiency synthesis of 2-substituted benzothiazoles via combining enzyme catalysis and photoredox catalysis in one-pot

2020 ◽  
pp. 104607
Author(s):  
Zeng-Jie Yang ◽  
Qing-Tian Gong ◽  
Yuan Yu ◽  
Wei-Fan Lu ◽  
Zhe-Ning Wu ◽  
...  
Keyword(s):  
Enzyme Catalysis ◽  
High Efficiency ◽  
Photoredox Catalysis ◽  
One Pot

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.

scholarly journals An entry to 2-(cyclobut-1-en-1-yl)-1H-indoles through a cyclobutenylation/deprotection cascade

2021 ◽  
Author(s):  
Philipp Natho ◽  
Zeyu Yang ◽  
Lewis Allen ◽  
Juliette Rey ◽  
Andrew J P White ◽  
...  
Keyword(s):  
Transition Metal ◽  
One Pot ◽  
Metal Free ◽  
Mild Conditions

A transition-metal-free strategy for the synthesis of 2-(cyclobut-1-en-1-yl)-1H-indoles under mild conditions is described herein. A series of substituted 2-(cyclobut-1-en-1-yl)-1H-indoles are accessed by a one-pot cyclobutenylation/deprotection cascade from N-Boc protected indoles....

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