1118-32-7Relevant academic research and scientific papers
Size-selective olefin hydrogenation by a Pd nanocluster provided in an apo-ferritin cage
Ueno, Takafumi,Suzuki, Masako,Goto, Toshiaki,Matsumoto, Tomoharu,Nagayama, Kuniaki,Watanabe, Yoshihito
, p. 2527 - 2530 (2004)
Deep penetration by substrates through the size-restricted channels of an apoferritin cage results in size-selective olefin hydrogenation at the Pd nanocluster core (see picture). The encapsulated zero-valent cluster is synthesized in situ by chemical reduction of PdII ions in the apoferritin cage.
Curtin-Hammett and steric effects in HOBt acylation regiochemistry
Brink, Benjamin D.,Defrancisco, Justin R.,Hillner, Julie A.,Linton, Brian R.
, p. 5258 - 5263 (2011)
While hydroxybenzotriazole is commonly used in a variety of bond-forming reactions, its acylation has been shown to produce a regiochemical (O vs N) mixture with complex kinetic behavior. Increased steric bulk on the electrophile favors formation of the o
Mechanistic evidence for intermolecular radical carbonyl additions promoted by samarium diiodide
Hansen, Anna Mette,Lindsay, Karl B.,Sudhadevi Antharjanam,Karaffa, Jakob,Daasbjerg, Kim,Flowers II, Robert A.,Skrydstrup, Troels
, p. 9616 - 9617 (2006)
In this work, mechanistic studies were performed to understand the SmI2/H2O-mediated coupling of N-acyl oxazolidinones with acrylates and acrylamides, providing γ-keto esters and amides, respectively. Our results provide experimental evidence that C-C bond formation via intermolecular radical addition reactions to carbonyl substrates can be promoted by samarium diiodide. Coupling reactions with N-cyclopropylcarbonyl-2-oxazolidinone suggest the α,β-unsaturated esters/amides are reduced by the low-valent lanthanide reagent and not the N-acyl oxazolidinones, as originially proposed (J. Am. Chem. Soc. 2005, 127, 6544). Rate measurements support the preferred reduction of an acrylate or acrylamide by SmI2/H2O in the presence of an N-acyl oxazolidinone. In the absence of the N-acyl oxazolidinone, SmI2/H2O promotes dimerization of the acrylates, whereas the C=C bond of the acrylamides is reduced. In addition, coupling of the Pfp ester of Cbz-protected phenylalanine with an acrylamide leads only to reduction of the acrylamide and recovered ester, whereas the same coupling with the N-acyl oxazolidinone derivative provides the γ-keto amides. These results imply that a pathway involving nucleophilic acyl substitution cannot take place and that a radical mechanism must be invoked to explain the C-C bond formation. We propose that the acrylate/acrylamide is reduced to a conjugated ketyl radical that adds to the exocyclic carbonyl group of the N-acyl oxazolidinone, activated through bidentate coordination to a lanthanide ion. Copyright
Synthesis and FTIR spectroscopic study of some N-monosubstituted propanamides
Antonovi?,Stojanovi?,Bo?i?,Nikoli?,Petrovi?
, p. 421 - 423 (1997)
In the present work we investigated the conformations of some N-mono-substituted propanamides of general formula CH3CH2CONHR, wherein R is chosen from n-(C1-C9)alkyl, cyclo(C3-C6)alkyl, some branched (C3-C6)alkyl or phenyl. The amides were synthesised by the well known Schotten-Baumann reaction-acylation of the corresponding amines with propionyl chloride. On the basis of FTIR data for diluted solutions (concentrations below 10-3 mol dm-3) of N-mono-substituted propanamides in carbon tetrachloride, chloroform, dichloromethane, or a 1:1.5 mixture of benzene and carbon tetrachloride the exact position of the N-H stretching band was established. For spectroscopic data the different conformational isomers were assigned and its structures unequivocally proven. These results are in good accordance with 1H NMR and MS data.
Variable NMR spin-lattice relaxation times in secondary amides: Effect of ramachandran angles on librational dynamics
Williams, John C.,McDermott, Ann E.
, p. 6248 - 6259 (1998)
Deuterium NMR spin-lattice relaxation times (T1Z) of N-deuterated microcrystalline secondary amides vary from less than 1 s to more than 500 s at room temperature. The main motion effecting relaxation is an out-of-plane libration of the amide, as indicated by temperature-dependent line shapes and anisotropic relaxation spectra. Over 25 amides were measured; they vary with respect to side chain sterics, hydrogen bond lengths, hydrogen bond geometry, and crystal packing. The temperature-dependent deuterium line shape and anisotropic relaxation rates indicate an out-of-plane angular deflection of approximately 10°; the angle is probably similar for the rapidly and slowly relaxing amides, while the apparent time constant for the motion probably varies dramatically. Deuterons in methylene groups on both sides of the amide group for caprylolactam and caprolactam also indicate an out-of-plane libration with relaxation rates faster than that of the amide deuteron, probably because the angular extent of the distortion is greater for the flanking α-deuteron than for the amide deuteron. Carbon relaxation measurements on lauryllactam indicate that the whole molecule librates to a comparable extent. Temperature-dependent relaxation rates for caprylolactam and caprolactam showed nonArrhenius monotonic increases in the relaxtion rates with increasing temperature, as expected for libration dynamics; furthermore the quadrupolar relaxation measurements support the assumption that the dominant spectral density contribution is above the Larmor frequency (i.e. T1Q is longer than T1Z). In aggregate, the data indicate that the motion effecting amide relaxation is a low-amplitude libration involving the entire molecule. Previous work on the librations of amides suggested that these librations are pronounced on the NMR time scale when the substance is near a phase transition; we report here that there is additionally a relation between the extent of libration and the structure. Comparison of the relaxation times to structures indicates that only amides with flanking alkyl groups on both sides (larger than a methyl group) exhibit extensive libration; furthermore only those amides with both flanking dihedral angles, φ{C2C1-NC(=O)} and ψ{N(O=)C-C1′C2′}, near -60° (～±40°) have fast spin-lattice relaxation. On the other hand, correlation between the deuterium relaxation times and hydrogen bond length nor geometry nor crystal packing was observed. Variation in the electronic structures of the conjugated amide groups was indirectly probed by measuring the chemical shift anisotropy of the amide carbonyl carbon, the deuterium quadrupolar coupling constant, and vibrational frequencies. These parameters did not vary dramatically, indicating that the electronic structure is not strongly variable; the modest variation did not correlate with deuterium relaxation rates. The chemical shift tensor elements were δ11 = 91.4 ±5, δ22 = 185 ± 8, and δ33 = 245 ± 3 ppm, the quadrupolar coupling constant and its anisotropy were 203 ± 10 kHz and 0.15 ± 0.02, the NH stretch frequency was 3300 ± 42 cm-1, and the carbonyl stretch frequency was 1644 ± 25 cm-1. We suggest a model in which the shape of the local potential associated with flanking alkyl groups leads to "overdamping" of the amide librational mode and generates slower (nanosecond) components in the vibrational frequency spectrum.
Nickel-Catalyzed Multicomponent Coupling Reaction of Alkyl Halides, Isocyanides and H2O: An Expedient Way to Access Alkyl Amides
Li, Qiao,Jin, Hongwei,Liu, Yunkui,Zhou, Bingwei
, p. 3466 - 3472 (2020)
We herein describe a Ni-catalyzed multicomponent coupling reaction of alkyl halides, isocyanides, and H2O to access alkyl amides. Bench-stable NiCl2(dppp) is competent to initiate this transformation under mild reaction conditions, thus allowing easy operation and adding practical value. Substrate scope studies revealed a broad functional group tolerance and generality of primary and secondary alkyl halides in this protocol. A plausible catalytic cycle via a SET process is proposed based on preliminary experiments and previous literature.
PROCESS FOR PREPARATION OF TERT-BUTYLAMINE AND PROPIONIC ACID SALTS FROM N-TERTIARY BUTYL ACRYLAMIDE
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Page/Page column 11-13, (2021/11/13)
Disclosed is a process (100) for conversion of N-tertiary butyl acrylamide to tert-butylamine and salts of propionic acid. The process comprises of first selectively reducing the vinylic double bond in N-tertiary butyl acrylamide by catalytic hydrogenation of an alcoholic solution of N-tertiary butyl acrylamide to provide N-tertiary buyl propanamide; recovering the hydrogenation catalyst by filtering the solution and treating the solution with an alkali to produce N-tertiary butylamine and corresponding alkali salt of propionic acid. The process converts of N-tertiary butyl acrylamide into value added products at milder reaction conditions, without producing any hazardous byproducts and effluents.
TfOH catalyzed One-Pot Schmidt–Ritter reaction for the synthesis of amides through N-acylimides
Singh, Garima,Dada, Ravikrishna,Yaragorla, Srinivasarao
supporting information, p. 4424 - 4427 (2016/09/13)
A One-Pot tandem Schmidt–Ritter process for the synthesis of amides has been developed using the super acid as catalyst. The in situ generated aryl/aliphatic nitriles from the reaction of aldehydes and sodium azide in the presence of TfOH and AcOH (Schmidt reaction) react with suitable alcohol (Ritter reaction) to give the amides. For the first time we observed that during the Schmidt process N-acylimides were generated along with nitriles, interestingly these N-acylimides also participated in the Ritter reaction.
Homoleptic zirconium amidates: Single source precursors for the aerosol-assisted chemical vapour deposition of ZrO2
Catherall, Amanda L.,Hill, Michael S.,Johnson, Andrew L.,Kociok-K?hn, Gabriele,Mahon, Mary F.
supporting information, p. 10731 - 10739 (2016/11/29)
We report the development of a true single source precursor (i.e. without any need for an exogenous source of oxygen) for the growth of zirconia thin films by aerosol-assisted chemical vapour deposition (AACVD) using an original family of zirconium(iv) amidate derivatives, which are easily prepared by protonolysis of [Zr(NMe2)4] with the free amide pro-ligands. In all but one case the reactions resulted in the isolation of the corresponding homoleptic eight-coordinate zirconium(iv)tetrakis(amidato) derivatives. Three of these species along with a tris(amidato)dimethylamido zirconium(iv) derivative have been characterised by single crystal X-ray diffraction analysis. The materials potential of the homoleptic compounds was identified through the application of design criteria derived from consideration of the existing knowledge base relating to the pyrolysis of wholly organic amides. In this manner the thermal decomposition of the homoleptic derivatives benefits from facile, molecularly imposed pyrolysis pathways, which provide for the privileged generation of volatile small molecule by-products and the production of contaminant-free solid oxide material. Thermogravimetric analysis, in conjunction with NMR spectroscopic analysis of the volatile products resulting from their thermal decomposition, indicated the potential of the homoleptic species as exquisite single source precursors to ZrO2 at moderate temperatures. The compound bearing both N- and C-iso-propyl substituents was, thus, applied as a true single source precursor under ambient pressure AACVD conditions. The resultant films, deposited on either SiO2-coated glass or quartz substrates, are smooth and comprise small and densely packed crystalline particulates that are shown by XRD to be primarily cubic ZrO2. Compositional analysis by X-ray photoelectron spectroscopy (XPS) revealed that the oxygen delivered, and the decomposition pathway provided, by the amidate ligand structure yields ZrO2 films which, though slightly sub-stoichiometric (ZrO1.8-1.9), contain undetectable levels of carbon incorporation.
Oxidative activation of dihydropyridine amides to reactive acyl donors
Funder, Erik Daa,Trads, Julie B.,Gothelf, Kurt V.
supporting information, p. 185 - 198 (2015/01/16)
Amides of 1,4-dihydropyridine (DHP) are activated by oxidation for acyl transfer to amines, alcohols and thiols. In the reduced form the DHP amide is stable towards reaction with amines at room temperature. However, upon oxidation with DDQ the acyl donor is activated via a proposed pyridinium intermediate. The activated intermediate reacts with various nucleophiles to give amides, esters, and thio-esters in moderate to high yields. This journal is
