1468-28-6Relevant articles and documents
Loss of benzaldehyde in the fragmentation of protonated benzoylamines: Benzoyl cation as a hydride acceptor in the gas phase
Chai, Yunfeng,Shao, Yunlong,Wang, Lu,Wang, Lin
, p. 664 - 671 (2017)
In electrospray ionization tandem mass spectrometry of protonated 1-benzoylamines (1-benzoylpiperadine, 1-benzoylmorpholine, and 1-benzoyl-4-methylpiperazine), the dominant fragmentation pathway was amide bond cleavage to form benzoyl cation and neutral amine. Meanwhile, in their fragmentations, an interesting loss of benzaldehyde (106?Da) was observed and identified to derive from hydride transfer reaction between the benzoyl cation and amine. A stepwise mechanism for loss of 106?Da (benzene and CO) could be excluded with the aid of deuterium labeling experiment. Theoretical calculations indicated that hydride transfers from amines (piperadine, morpholine, and 1-methylpiperazine) to benzoyl cation were thermodynamically permitted, and 1-methylpiperazine was the best hydride donor among the 3 amines. The mass spectrometric experimental results were consistent with the computational results. The relative abundance of the iminium cation (relative to the benzoyl cation) in the fragmentation of protonated 1-benzoyl-4-methylpiperazine was higher than that in the fragmentation of the other 2 protonated 1-benzoylamines. By comparing the fragmentations of protonated 1-benzyl-4-methylpiperazine and protonated 1-benzoyl-4-methylpiperazine and the energetics of their hydride transfer reactions, this study revealed that benzoyl cation was a hydride acceptor in the gas phase, but which was weaker than benzyl cation.
Synthesis of tertiary benzamides via Pd-catalyzed coupling of arylboronic esters and carbamoyl chlorides
Lysen, Morten,Kelleher, Susan,Begtrup, Mikael,Kristensen, Jesper Langgaard
, p. 5342 - 5343 (2005)
Ortho-substituted arylboronic esters are efficiently coupled with carbamoyl chlorides under Pd-catalysis to give tertiary benzamides.
Silica nanosphere-supported palladium(II) furfural complex as a highly efficient and recyclable catalyst for oxidative amination of aldehydes
Sharma,Sharma, Shivani
, p. 1292 - 1304 (2014)
The present work reports the fabrication of a novel and highly efficient silica nanospheres-based palladium catalyst (SiO2@APTES@Pd-FFR) via immobilization of a palladium complex onto silica nanospheres functionalized with 3-aminopropyltriethoxysilane (APTES), and its catalytic application for the oxidative amination of aldehydes to yield commercially important amides. The structure of the nano-catalyst was confirmed by Solid-state 13C CPMAS and 29Si CPMAS NMR spectroscopy, Brunauer-Emmett-Teller (BET) surface area analysis, Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray fluorescence spectroscopy (ED-XRF), Atomic absorption spectroscopy (AAS), Transmission electron microscopy (TEM) and elemental analysis. The nano-catalyst was found to be highly effective for the oxidative amination of aldehydes using hydrogen peroxide as an environmentally benign oxidant to give amides. The effect of various reaction parameters such as temperature, amount of catalyst, reaction time, type of solvent, oxidant used, substrate to oxidant ratio etc. have been demonstrated to achieve high catalytic efficacy. Moreover, this nanostructured catalyst could be recovered with simplicity and reused for several cycles without any significant loss in its catalytic activity. In addition, the stability of the reused nano-catalyst was proved by FT-IR and HRTEM techniques. It is worth noting that the features of mild reaction conditions, simple work-up procedure, high product yield, no use of toxic organic solvents, high turn-over frequency (TOF), and easy recovery and reusability of the present quasi-homogeneous nano-catalyst make this protocol an attractive alternative to the existing catalytic methods for the oxidative amination of aldehydes to furnish industrially important amides. The Royal Society of Chemistry 2014.
Development of palladium catalysts immobilized on supported phosphonium ionic liquid phases
Urbán, Béla,Skoda-F?ldes, Rita
, p. 302 - 306 (2019)
The application of heterogeneous palladium catalysts supported on phosphonium ion modified silica was investigated in aminocarbonylation reactions of aryl iodides. In contrast to catalysts immobilized on supports decorated with imidazolium ions, the application of phosphonium type supported ionic liquid phases made it possible to carry out double carbonylation with good selectivity in apolar toluene which led to a considerable decrease in the amount of leached palladium. An even better stabilization of the palladium catalyst could be achieved by introducing dicationic organic moieties incorporating both imidazolium and phosphonium ions on the surface of the support. At the same time, the former catalyst, obtained from the supported phosphonium ionic liquid phase was found to be superior in monocarbonylations. The amide products were obtained in good yields by the proper choice of the reaction conditions, such as reaction temperature and pressure and that of the base.
N-BENZOYL O,O-DIALKYL PHOSPHORANILIDATES: REACTION WITH O- AND N-NUCLEOPHILES
Baraniak, Janina,Stec, Wojciech J.
, p. 4193 - 4196 (1991)
Solvolysis of mixed phosphoric-carboxylic N-phenylimides occurs with exclusive attack of nucleophiles at the carbonyl carbon centre and is accompanied by phosphoryl N->O migration.
Acylation of piperidine and morpholine with phenyl benzoates in the mixtures water-2-propanol and water-dioxane
Kochetova,Kalinina,Kuritsyn,Kustova
, p. 1416 - 1423 (2015)
Kinetics of acylation of piperidine and morpholine with 4-nitro- and 2,6-dinitrophenyl benzoates was studied in binary systems water-2-propanol and water-dioxane. Structural and energy characteristics of solvate complexes of morpholine and piperidine with the components of the mixed solvents were calculated. Kinetic regularities of acylation are considered from the viewpoint of specific solvation of amines.
Pd-PEPPSI: A general Pd-NHC precatalyst for Buchwald-Hartwig cross-coupling of esters and amides (transamidation) under the same reaction conditions
Shi, Shicheng,Szostak, Michal
, p. 10584 - 10587 (2017)
Amides are of fundamental interest in many fields of chemistry involving organic synthesis, chemical biology and biochemistry. Here, we report the first catalytic Buchwald-Hartwig coupling of both common esters and amides by highly selective C(acyl)-X (X = O, N) cleavage to rapidly access aryl amide functionality via a cross-coupling strategy. Reactions are promoted by versatile, easily prepared, well-defined Pd-PEPPSI type precatalysts, and proceed in good to excellent yields and with excellent chemoselectivity for the acyl bond cleavage. The method is user friendly because it employs commercially-available, moisture- and air-stable precatalysts. Notably, for the first time we demonstrate selective C(acyl)-N and C(acyl)-O cleavage/Buchwald-Hartwig amination under the same reaction conditions, which allows for streamlining amide synthesis by avoiding restriction to a particular acyl metal precursor. Of broad interest, this study opens the door to using a family of well-defined Pd(ii)-NHC precatalysts bearing pyridine "throw-away" ligands for the selective C(acyl)-amination of bench-stable carboxylic acid derivatives.
Ionic Complexes of Tetra- and Nonanuclear Cage Copper(II) Phenylsilsesquioxanes: Synthesis and High Activity in Oxidative Catalysis
Bilyachenko, Alexey N.,Kulakova, Alena N.,Levitsky, Mikhail M.,Korlyukov, Alexander A.,Khrustalev, Victor N.,Vologzhanina, Anna V.,Titov, Aleksei A.,Dorovatovskii, Pavel V.,Shul'pina, Lidia S.,Lamaty, Frédéric,Bantreil, Xavier,Villemejeanne, Beno?t,Ruiz, Cindy,Martinez, Jean,Shubina, Elena S.,Shul'pin, Georgiy B.
, p. 4437 - 4447 (2017)
Herein, we describe an approach to cage metallasilsesquioxanes by self-assembly with 1,2-bis(diphenylphosphino)ethane as a key reactant. This approach allowed us to achieve a unique family of complexes that includes anionic tetra- and nonanuclear cage copper(II) sodium silsesquioxane and cationic copper(I) 1,2-bis(diphenylphosphino)ethane components. Additional representatives of this intriguing metallasilsesquioxane family (Cu9Na6 and Cu9Na3Cs3) were obtained through the replacement of the original ethanol-based reaction medium by DMSO. The fascinating structural peculiarities of all products were established by using XRD and topological studies. Initial tests for the application of the synthesized complexes as catalysts revealed their very high activity in the homogeneous oxidation of alkanes and alcohols to produce alkyl hydroperoxides, ketones, and amides.
Iron-Catalyzed Amide Formation from the Dehydrogenative Coupling of Alcohols and Secondary Amines
Lane, Elizabeth M.,Uttley, Katherine B.,Hazari, Nilay,Bernskoetter, Wesley
, p. 2020 - 2025 (2017)
The five-coordinate iron(II) hydride complex (iPrPNP)Fe(H)(CO) (iPrPNP = N[CH2CH2(PiPr2)]2) selectively catalyzes the dehydrogenative intermolecular coupling of alcohols and secondary amines to form tertiary amides. This is the most productive base-metal catalyst for dehydrogenative amidation reported to date, in some cases achieving up to 600 turnovers. The catalyst works well for sterically undemanding amines and alcohols or cyclic substrates and is particularly effective in the synthesis of formamides from methanol. However, the catalyst performance declines rapidly with the incorporation of large substituents on the amine or alcohol substrate. Variable-temperature NMR spectroscopic studies suggest that the catalyst resting state is an off-cycle iron(II) methoxide species, (iPrPN(H)P)Fe(H)(OCH3)(CO), resulting from addition of methanol across the Fe-N bond of (iPrPNP)Fe(H)(CO). This reversibly formed iron(II) methoxide complex is favored at mild temperatures but eliminates methanol upon heating.
TBAI-catalyzed C–N bond formation through oxidative coupling of benzyl bromides with amines: a new avenue to the synthesis of amides
Kumar, Dhirendra,Maury, Suresh Kumar,Kumari, Savita,Kamal, Arsala,Singh, Himanshu Kumar,Singh, Sundaram,Srivastava, Vandana
supporting information, p. 424 - 432 (2022/02/09)
A new green approach for the synthesis of amide through TBAI-catalyzed oxidative coupling of benzyl bromides with amine was developed in the presence of tert-butyl hydroperoxide (TBHP) as an oxidant. Various electron-donating and withdrawing groups containing benzyl bromides and various amines, were subjected to the reaction and transformed to the corresponding amide in good to excellent yields.
Chromium-catalyzed ligand-free amidation of esters with anilines
Chen, Changpeng,Ling, Liang,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 762 - 766 (2021/04/14)
Amides are important structural motifs in pharmaceutical and agrochemical chemistry because of the intriguing biological active properties. We report here the amidation of commercially available esters with anilines that was promoted by low-cost and air-stable chromium(III) pre-catalyst combined with magnesium, providing access to amides. This reaction occurs without the use of external ligands in a simple operation. Mechanistic studies indicate that a reactive aminated Cr species responsible for the amidation can be considered, which may be formed by reaction of low-valent Cr with aniline followed by reduction with hydrogen evolution.
Benzyne-Mediated Esterification Reaction
Li, Yang,Shi, Jiarong,Zhao, Jinlong
supporting information, p. 7274 - 7278 (2021/10/01)
A benzyne-mediated esterification of carboxylic acids and alcohols under mild conditions has been realized, which is made possible via a selective nucleophilic addition of carboxylic acid to benzyne in the presence of alcohol. After a subsequent transesterification with alcohol, the corresponding esters can be produced efficiently. This benzyne-mediated protocol can be used on the modification of Ibuprofen, cholesterol, estradiol, and synthesis of nandrolone phenylpropionate. In addition, benzyne can also be used to promote lactonization and amidation reaction.