16118-22-2Relevant academic research and scientific papers
Synthesis of a novel class of β-lactam derivatives of 1-aminophosphonates by staudinger ketene-imine [2+2]-cycloaddition reaction
Kaboudin, Babak,Afsharinezhad, Mohammad Bagher
, p. 3504 - 3508 (2010)
A novel class of β-lactam derivatives of 1-aminophosphonates was synthesized by Staudinger [2+2] cycloaddition reaction of ketenes with imines derived from 1-aminophosphonates. Treatment of aromatic aldehydes with ammonia and diethyl phosphite followed by
Synthesis of a Molybdenum Hydrido(hydrogermylene) Complex and Its Conversion to a Germylyne Complex: Another Route through Dehydrogenation with Nitriles
Dhungana, Tara Prasad,Hashimoto, Hisako,Ray, Mausumi,Tobita, Hiromi
, p. 4350 - 4361 (2020)
A molybdenum germylene complex having Mo-H and Ge-H bonds, Cp*(CO)2(H)Mo=Ge(H){C(SiMe3)3} (1), was synthesized by the reaction of a methyl molybdenum complex with a trihydrogermane and was converted to a germylyne complex, Cp*(CO)2MoGe{C(SiMe3)3} (2), via dehydrogenation with aryl isocyanates under mild heating. A similar conversion from the same germylene complex into the germylyne complex also occurred using nitriles instead of isocyanates, while releasing imines via a Mo-Ge-N three-membered ring complex Cp*(CO)2Mo[κ2(N,Ge)Ge-(N=CHR){C(SiMe3)3}] (4, R = Me and aryl groups) as an intermediate. Formation of imines was confirmed by a trapping experiment with BPh3, which afforded a BPh3-imine adduct. In the case of aryl nitriles, the corresponding three-membered ring intermediates were converted into the germylyne complex efficiently by blue LED light irradiation. TD-DFT calculations on the three-membered-ring intermediate suggest that the role of the LED light is to induce CO ligand dissociation from the intermediate via a metal-to-ligand-charge-transfer (MLCT) transition.
Structural characteristics and catalytic performance of nanostructured Mn-doped CeO2 solid solutions towards oxidation of benzylamine by molecular O2
Rangaswamy, Agolu,Venkataswamy, Perala,Devaiah, Damma,Ramana, Singuru,Reddy, Benjaram M.
, p. 136 - 147 (2017)
This work reports a thorough investigation of nanosized Mn-doped ceria (Ce0.7Mn0.3O2-δ, CM) as an efficient catalyst for oxidation of benzylamine under solvent-free conditions. These catalysts were prepared by a coprecipitation method followed by calcination at 773 and 1073?K. Effect of Mn doping was examined by a variety of characterization techniques. XRD results confirmed formation of single-phase Ce-O-Mn solid solution, and TEM studies showed nanosized nature of particles. BET surface area of CeO2 was significantly enhanced after Mn incorporation. Raman, XPS and H2-TPR results revealed that Mn cations in ceria lattice increase concentration of structural oxygen vacancies and reducibility of ceria. Among various catalysts, the CM calcined at 773?K exhibited a high conversion (～71%), product selectivity (～99.8%), and excellent stability. The better performance has been proved to be due to synergetic interaction between Ce and Mn ions thereby enhanced surface area, improved reducibility, and increased surface adsorbed oxygen species.
Catalytic aerobic photooxidation of primary benzylic amines using hindered acridinium salts
Nicolas, Cyril,Herse, Christelle,Lacour, Jér?me
, p. 4605 - 4608 (2005)
Hindered acridinium cations, simply prepared by the addition of primary amines to the known methylium tris(2,6-dimethoxyphenyl) cation, catalyze the aerobic photooxidation of primary benzyl amines into benzylimines. A mechanistic rationale for the electron-transfer process is proposed.
Rapid combinatorial access to macrocyclic ansapeptoids and ansapeptides with natural-product-like core structures
De Greef, Michiel,Abeln, Sahan,Belkasmi, Khalid,Doemling, Alexander,Orru, Romano V. A.,Wessjohann, Ludger A.
, p. 3997 - 4004 (2006)
14-Membered ansa-cyclopeptide alkaloids are among the most abundant natural macrocycles and thus valuable templates for diversity-oriented synthesis with biological relevance. A rapid synthesis of the core structure is conceivable by a combination of an Ugi four-component reaction with bifunctional building blocks to form the dipeptoid part, followed by a suitable macrocyclization reaction. The latter step is crucial, and an uncommon macroetherification gave the best results. The use of ammonium salts allows direct access to peptides instead of peptoids. Depending on the substitution pattern, some cyclopeptoids show planar chirality despite free rotation of the phenylene group. Georg Thieme Verlag Stuttgart.
The mechanism of pyrolysis of benzyl azide: Spectroscopic evidence for benzenemethanimine formation
Pinto, Rui M.,Guerra, Mauro,Copeland, Grant,Olariu, Romeo I.,Rodrigues, Paula,Teresa Barros,Lourdes Costa,Dias, António A.
, p. 4118 - 4126 (2015)
We study the gas-phase pyrolysis of benzyl azide (BA, C6H5CH2N3) using ultraviolet photoelectron spectroscopy (UVPES) and matrix-isolation infrared (IR) spectroscopy, together with electronic structure calculations and Rice-Ramsperger-Kassel-Marcus (RRKM) calculations. It is found that BA decomposes via N2 elimination at ca. 615 K, primarily yielding benzenemethaninime. Other end products include HCN and C6H6. N-Methyleneaniline is not detected, although its formation at higher temperature is foreseen by RRKM calculations.
Kinetics and mechanism of the oxidation of substituted benzylamines by hexamethylenetetramine-bromine
Dubey, Rashmi,Kothari, Seema,Banerji, Kalyan K.
, p. 103 - 107 (2002)
The oxidation of substituted benzylamines by hexamethylenetetramine-bromine (HABR) to the corresponding aldimines is first order with respect to each the amine and HABR. It is proposed that HABR itself is the reactive oxidizing species. The oxidation of deuterated benzylamine (PhCD2NH2) indicated a substantial kinetic isotope effect (kH/kD = 5.60 at 293 K). This confirmed the cleavage of an α-C-H bond in the rate-determining step. Correlation analyses of the rates of oxidation of 20 monosubstituted benzylamines were performed with various single-and multi-parametric equations. The rates of the oxidation showed excellent correlations in terms of the Yukawa-Tsuno and Brown equations. The polar reaction constants were negative. The oxidation exhibited extensive cross-conjugation, in the transition state, between the electron-donating substituents and the reaction centre. A mechanism involving a hydride ion transfer from the amine to HABR, in the rate-determining step, is proposed. Copyright
Synergistic Nanostructured MnOx/TiO2 Catalyst for Highly Selective Synthesis of Aromatic Imines
Sudarsanam, Putla,K?ckritz, Angela,Atia, Hanan,Amin, Mohamad Hassan,Brückner, Angelika
, p. 1990 - 1997 (2021)
This work reports the development of a synergistic nanostructured MnOx/TiO2 catalyst, with highly dispersed MnOx nanoparticles (4.5±1 nm) on shape-controlled TiO2 nanotubes (8–11 nm width and 120–280 nm length), for selective synthesis of valuable aromatic imines at industrially important conditions. Pristine TiO2 nanotubes exhibited 97 % imine selectivity at a 38.3 % benzylamine conversion, whereas very low imine selectivity was obtained over commercial TiO2 materials, indicating the catalytic significance of shape-controlled TiO2 nanotubes. The MnOx nanoparticle/TiO2 nanotube (10 wt% Mn) catalyst calcined at 400 °C showed the best activity with 95.6 % benzylamine conversion and 99.9 % imine selectivity. This catalyst exhibited good recyclability for four times and is effective for converting numerous benzylamines into higher yields of imines. The high catalytic performance of MnOx/TiO2 nanotubes was attributed to higher number of redox sites (Mn3+), high dispersion of Mn species, and shape-controlled structure of TiO2, indicating that this catalyst could be a promising candidate for selective oxidation reactions.
Kinetic Resolution of α-Silyl-Substituted Allylboronate Esters via Chemo- and Stereoselective Allylboration of Aldehydes
Park, Jinyoung,Jung, Yongsuk,Kim, Jeongho,Lee, Eunsung,Lee, Sarah Yunmi,Cho, Seung Hwan
supporting information, p. 2371 - 2376 (2020/12/01)
We describe the kinetic resolution of α-silyl-substituted allylboronate esters via chiral phosphoric acid-catalyzed chemo-, diastereo- and enantioselective allylboration of aldehydes. This process provides two synthetically versatile enantioenriched compo
Enantioselective Allylation of Cyclic and In Situ Formed N-Unsubstituted Imines with Tetraol-Protected Allylboronates
Ullrich, Patrick,Schlamkow, Max A.,Choi, Ching-Yi,Kerkenpa?, Hannah,Hen?en, Birgit,Pietruszka, J?rg
supporting information, p. 6254 - 6257 (2021/11/03)
Tetraol-protected α-chiral allylboronates are utilized in diastereo- and enantioselective transformations of cyclic imines (up to 98 %, d.r. 97 : 3, e.r. 99 : 1). An application to in situ formed N-unsubstituted imines gives in a consecutive one-pot sequence selective access to all four stereoisomers of the homoallylamine within minutes (up to 88 %, d.r. 81 : 19, e.r. 99 : 1). These results underline the usability, tuneability and stability of tetraol-based allylboronates.
