Latest News on Amides Research: Sep – 2019

Rate Processes and Nuclear Magnetic Resonance Spectra. II. Hindered Internal Rotation of Amides

Mathematical strategies area unit conferred for calculative rate constants of processes that slim nuclear resonance absorption lines having separate elements. High resolution nucleon spectra show that the R1CO‐NR2R3 skeletons of N,N‐dimethylformamide (DMF) and N,N‐dimethylacetamide (DMA) area unit flat and counsel that N‐methylformamide, N‐methylacetamide, N‐methylformanilide and N‐methylacetanilide exist preponderantly in one configuration.  [1]

Direct Synthesis of Amides from Alcohols and Amines with Liberation of H2

Given the widespread importance of amides in organic chemistry and chemical systems, Associate in Nursing economical synthesis that avoids wasteful use of ratio coupling reagents or corrosive acidic and basic media is very fascinating. we have a tendency to report a reaction within which primary amines are directly acylated by equimolar amounts of alcohols to provide amides and molecular element (the solely products) in high yields and high turnover numbers. This reaction is catalyzed by a atomic number 44 complicated supported a dearomatized PNN-type matter [where PNN is 2-(di-tert-butylphosphinomethyl)-6-(diethylaminomethyl)pyridine], and no base or acid promoters are needed.  [2]

An Alternative Procedure for the Aluminum-Mediated Conversion of Esters to Amides

A convenient technique has been developed for directly changing esters to amides victimization reagents derived from the reaction of trimethylaluminum with sal ammoniac, methylamine complex or dimethylamine complex. [3]

Straightforward access to N-trifluoromethyl amides, carbamates, thiocarbamates and ureas

Amides and connected carbonyl derivatives are of central importance across the physical and life sciences1,2. As a key biological building block, the steadiness and conformation of amides have an effect on the structures of peptides and proteins also as their biological operate. additionally, amide-bond formation is one among the foremost oft used chemical transformations3,4. Given their omnipresence, a technology that’s capable of modifying the basic properties of amides while not compromising on stability might have goodly potential in pharmaceutical, agrochemical and materials science. [4]

Study on the Application of Beckmann Rearrangement in the Synthesis of Amides from Oximes

In order to arrange amides beneath moderate and environment-friendly conditions victimization Beckmann arrangement, we tend to replaced ancient liquid-acid catalysts with Nafion perfluorinated sulfonic acid resins. we tend to used diphenylketone organic compound because the model substrate and dispensed experimental studies to explore the best reaction conditions for Beckmann arrangement. [5]

Reference

[1] Gutowsky, H.S. and Holm, C.H., 1956. Rate processes and nuclear magnetic resonance spectra. II. Hindered internal rotation of amides. The Journal of Chemical Physics, 25(6), pp.1228-1234. (Web Link)

[2] Gunanathan, C., Ben-David, Y. and Milstein, D., 2007. Direct synthesis of amides from alcohols and amines with liberation of H2. Science, 317(5839), pp.790-792. (Web Link)

[3] Levin, J.I., Turos, E. and Weinreb, S.M., 1982. An alternative procedure for the aluminum-mediated conversion of esters to amides. Synthetic Communications, 12(13), (Web Link)

[4] Straightforward access to N-trifluoromethyl amides, carbamates, thiocarbamates and ureas
Thomas Scattolin, Samir Bouayad-Gervais & Franziska Schoenebeck
Naturevolume 573, pages102–107 (2019) (Web Link)

[5] Liu, D., Shao, J., Zhu, J., Yuan, C. and Zhang, Y. (2018) “Study on the Application of Beckmann Rearrangement in the Synthesis of Amides from Oximes”, International Research Journal of Pure and Applied Chemistry, 15(4), (Web Link)

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