Reagent-free aerobic oxidative synthesis of amides from aldehydes and isothiocyanates

2021 ◽  
Author(s):  
Jiang-Sheng Li ◽  
Xin-Yun Xie ◽  
Si Jiang ◽  
Pan-Pan Yang ◽  
Zhi-Wei Li ◽  
...  
Keyword(s):  
Carboxylic Acids

A reagent-free autoxidative reaction of aldehydes with isothiocyanates is developed to readily access amides, involving capture of carboxylic acids in situ generated from aldehydes by isothiocyanates as both coupling mediators and amine surrogates.

scholarly journals Combined Photoredox and Carbene Catalysis for the Synthesis of Ketones from Carboxylic Acids

2020 ◽  
Author(s):  
Anna Davies ◽  
keegan fitzpatrick ◽  
Rick Betori ◽  
Karl Scheidt
Keyword(s):  
Carboxylic Acids ◽  
Late Stage ◽  
Pharmaceutical Compounds ◽  
Single Electron ◽  
Photoredox Catalysis ◽  
Radical Coupling ◽  
Electron Reduction

Disclosed herein is the development of a novel single-electron reduction of acyl azoliums for the formation of ketones from carboxylic acids. Facile construction of the acyl azolium <i>in situ</i> followed by a radical-radical coupling was made possible using merged NHC-photoredox catalysis. The utility of this protocol in synthesis was demonstrated in the late-stage functionalization of a variety of pharmaceutical compounds.

scholarly journals Poly(methylhydrosiloxane) as a green reducing agent in organophosphorus-catalysed amide bond formation

2017 ◽  
Vol 15 (30) ◽  
pp. 6426-6432 ◽  
Author(s):  
Daan F. J. Hamstra ◽  
Danny C. Lenstra ◽  
Tjeu J. Koenders ◽  
Floris P. J. T. Rutjes ◽  
Jasmin Mecinović
Keyword(s):  
Carboxylic Acids ◽  
Phosphine Oxide ◽  
Bond Formation ◽  
Reducing Agent ◽  
Amide Bond ◽  
Amide Bond Formation ◽  
Amidation Reaction

In situ reduction of phosphine oxide by poly(methylhydrosiloxane) leads to efficient amidation reaction between carboxylic acids and amines.

ChemInform Abstract: Esterification of Carboxylic Acids Catalyzed by in situ Generated Tetraalkylammonium Fluorides.

ChemInform ◽  
2010 ◽  
Vol 33 (11) ◽  
pp. no-no
Author(s):  
Takashi Ooi ◽  
Hayato Sugimoto ◽  
Kanae Doda ◽  
Keiji Maruoka
Keyword(s):  
Carboxylic Acids

The reactivity of platinum hydrides in the selective hydrogenation of acetic acid over Pt-ReOx/TiO2 catalysts

2020 ◽  
Vol 20 (6) ◽  
pp. 426-432
Author(s):  
N. V. Makolkin ◽  
H. U. Kim ◽  
E. A. Paukshtis ◽  
J. Jae ◽  
B. S. Bal’zhinimaev
Keyword(s):  
Acetic Acid ◽  
Absorption Band ◽  
Electronic State ◽  
Carboxylic Acids ◽  
Selective Hydrogenation ◽  
High Reactivity ◽  
Absorption Bands ◽  
In Situ Drifts ◽  
High Frequencies

In situ DRIFTS was employed to investigate the reaction of hydrogen with supported subnanometer Pt-ReOx species that are active in the hydrogenation of carboxylic acids. Absorption bands of platinum hydrides in the region of 2025–2043 cm–1 were detected; high reactivity of the hydrides toward the adsorbed acetic acid was revealed. In the process, the absorption band of platinum hydride shifted to high frequencies and increased in intensity due to the influence of adjacent acetates on the electronic state of platinum. It was found that in a hydrogen medium the intensity of platinum hydride bands sharply increases after the adsorption of acetic acid and then gradually decreases owing to the reaction of the hydrides with surface acetates.

Oxidative Cyclization of β,γ-Unsaturated Carboxylic Acids Using Hypervalent Iodine Reagents: An Efficient Synthesis of 4-Substituted Furan-2-ones

Synthesis ◽  
2017 ◽  
Vol 49 (13) ◽  
pp. 2907-2912 ◽  
Author(s):  
Kensuke Kiyokawa ◽  
Satoshi Minakata ◽  
Kenta Takemoto ◽  
Shunsuke Yahata ◽  
Takumi Kojima
Keyword(s):  
Organic Chemistry ◽  
Carboxylic Acids ◽  
Present Method ◽  
Medicinal Chemistry ◽  
Oxidative Cyclization ◽  
Hypervalent Iodine ◽  
Efficient Synthesis ◽  
Substitution Pattern ◽  
Unsaturated Carboxylic Acids

The oxidative cyclization of β-substituted β,γ-unsaturated carboxylic acids using a hypervalent iodine reagent to provide 4-substituted furan-2-one products, is reported. In this cyclization, the use of a highly electrophilic PhI(OTf)2, which is in situ prepared from PhI(OAc)2 and Me3SiOTf, is crucial. Depending on the substitution pattern at the α-position of the substrates, furan-2(5H)-ones or furan-2(3H)-ones are produced. Thus, the present method offers a useful tool for accessing various types of 4-substituted furan-2-ones that are important structural motifs in the field of organic chemistry and medicinal chemistry.

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