- Aerobic oxidation of primary amines to amides catalyzed by an annulated mesoionic carbene (MIC) stabilized Ru complex
-
Catalytic aerobic oxidation of primary amines to the amides, using the precatalyst [Ru(COD)(L1)Br2] (1) bearing an annulated π-conjugated imidazo[1,2-a][1,8]naphthyridine-based mesoionic carbene ligand L1, is disclosed. This catalytic protocol is distinguished by its high activity and selectivity, wide substrate scope and modest reaction conditions. A variety of primary amines, RCH2NH2 (R = aliphatic, aromatic and heteroaromatic), are converted to the corresponding amides using ambient air as an oxidant in the presence of a sub-stoichiometric amount of KOtBu in tBuOH. A set of control experiments, Hammett relationships, kinetic studies and DFT calculations are undertaken to divulge mechanistic details of the amine oxidation using 1. The catalytic reaction involves abstraction of two amine protons and two benzylic hydrogen atoms of the metal-bound primary amine by the oxo and hydroxo ligands, respectively. A β-hydride transfer step for the benzylic C-H bond cleavage is not supported by Hammett studies. The nitrile generated by the catalytic oxidation undergoes hydration to afford the amide as the final product. This journal is
- Yadav, Suman,Reshi, Noor U Din,Pal, Saikat,Bera, Jitendra K.
-
p. 7018 - 7028
(2021/11/17)
-
- Primary fatty acid amide preparation method
-
The present invention provides a primary fatty acid amide preparation method. According to the present invention, under the action of a single auxiliary agent phosphine-containing transition metal catalyst or a combined auxiliary agent comprising a phosphine-free transition metal catalyst and a phosphine-containing ligand, terminally substituted olefin or cyclo-olefin, carbon monoxide and an ammonium salt are subjected to a hydrogen carboamidation reaction so as to prepare the primary fatty acid amide compound in one step; the raw material and the catalyst of the reaction are inexpensive and easy to obtain, and the synthesis process is simple, such that the synthesis cost is substantially reduced; the preparation method has characteristics of mild reaction condition and high yield, and issuitable for industrial production; and the raw material and the catalyst of the reaction are clean, non-toxic and low environment pollution.
- -
-
Paragraph 0267-0269
(2018/10/19)
-
- Palladium-catalyzed regiodivergent hydroaminocarbonylation of alkenes to primary amides with ammonium chloride
-
Palladium-catalyzed hydroaminocarbonylation of alkenes for the synthesis of primary amides has long been an elusive aim. Here, we report an efficient catalytic system which enables inexpensive NH4Cl to be utilized as a practical alternative to gaseous ammonia for the palladium-catalyzed alkene-hydroaminocarbonylation reaction. Through appropriate choice of the palladium precursors and ligands, either branched or linear primary amides can be obtained in good yields with good to excellent regioselectivities. Primary mechanistic studies were conducted and disclosed that electrophilic acylpalladium species were capable of capturing the NH2-moiety from ammonium salts to form amides in the presence of CO with NMP as a base.
- Gao, Bao,Zhang, Guoying,Zhou, Xibing,Huang, Hanmin
-
p. 380 - 386
(2018/01/12)
-
- Lizard epidermal gland secretions. II. Chemical characterization of the generation gland secretion of the sungazer, cordylus giganteus
-
In lizards, the epidermal glands of the femoral and precloacal regions are involved in the production of semiochemicals. In addition to its femoral glands, the giant girdled lizard, or sungazer, Cordylus giganteus, which is endemic to South Africa, has generation glands as an additional potential source of semiochemicals. These epidermal glands are described as glandular scales that overlay the femoral glands and are included in the normal epidermal profile located in the femoral (thigh) and anterior antebrachial (fore-leg) regions of the male sungazer. GC-MS analysis of the generation gland secretions and the trimethylsilyl derivatives of some of the steroidal constituents was employed to identify 59 constituents, including alkenes, carboxylic acids, alcohols, ketones, aldehydes, esters, amides, nitriles, and steroids. The quantitative differences of the volatile constituents of the fore- and hind-leg generation glands were compared between individuals. This is the first report on the chemical composition of generation glandular material of lizards.
- Louw, Stefan,Burger, Ben V.,Le Roux, Maritha,Van Wyk, Johannes H.
-
p. 1364 - 1369
(2011/08/09)
-
- Synthetic libraries of tyrosine-derived bacterial metabolites
-
The preparation of a collection of 131 small molecules, reminiscent of families of long chain N-acyl tyrosines, enamides and enol esters that have been isolated from heterologous expression of environmental DNA (eDNA) in Escherichia coli, is reported. The synthetic libraries of N-acyl tyrosines and their 3-keto counterparts were prepared via solid-phase routes, whereas the enamides and enol esters were synthesized in solution-phase.
- Georgiades, Savvas N.,Clardy, Jon
-
supporting information; experimental part
p. 3117 - 3121
(2009/04/03)
-
- 9(Z)-Octadecenamide and Fatty Amides by Bacillus megaterium (B-3437) Conversion of Oleic Acid
-
9(Z)-Octadecenamide, hexadecenamide, tetradecenamide and tetradecanamide were produced by a novel bioconversion of oleic acid with Bacillus megaterium NRRL B-3437.Although chemical synthesis is more practical, the bioconversion to fatty amides (5-7percent of total recovered lipids) was unique for its requirement of both enzymatic catalysis and equimolar oleic acid / ammonium salt substrates.Purified octadecenamide was obtained by silica gel and high-pressure liquid chromatographic procedures and was characterized by gas chromatography, mass spectrometry, infrared and nuclear magnetic resonance.KEY WORDS: Bacillus megaterium (B-3437), bioconversion, fatty amides, hexadecenamide, 9(Z)-octadecenamide, oleic acid.
- Kaneshiro, T.,Vesonder, R. F.,Peterson, R. E.,Weisleder, D.,Bagby, M. O.
-
p. 491 - 494
(2007/10/02)
-