1468-28-6Relevant academic research and scientific papers
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.
A new and efficient one-pot synthesis of aromatic alkynyl ketones from aromatic esters
Yim, Sang Jun,Kwon, Chan Ho,An, Duk Keun
, p. 5393 - 5395 (2007)
The reaction of aromatic esters with alkynyllithiums in the presence of lithium morpholinide and BF3·OEt2 gave aromatic alkynyl ketones in good yield (78-87%).
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.
Catalytic Formation of α-Aryl Ketones by C-H Functionalization with Cyclic Alkenyl Carbonates and One-Pot Synthesis of Isocoumarins
Hara, Yusuke,Onodera, Shunsuke,Kochi, Takuya,Kakiuchi, Fumitoshi
, p. 4850 - 4853 (2015)
We report here a method for direct catalytic introduction of simple α-acylalkyl groups via rhodium-catalyzed C-H functionalization with cyclic alkenyl carbonates, synthetic equivalents to enolates bearing leaving groups. The reaction proceeded smoothly without using bases to give α-aryl ketones in high yields. Various nitrogen-containing aromatic rings and amide groups serve as directing groups. 3-Substituted isocoumarins can also be prepared by one-pot C-H functionalization/cyclization.
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.
The magnetic graphene oxide/NHC catalyzed aerobic direct amidation and cross-dehydrogenative coupling of aldehydes
Sepahvand, Heshmatollah,Ghasemi, Elnaz,Sharbati, Mohammad,Mohammadi, Melika Sadat,Arshadi Pirlar, Maghsoud,Shahverdizadeh, Gholam Hossein
, p. 16555 - 16565 (2019)
In this paper, the synthesis of a novel imidazolium based N-heterocyclic carbene (NHC) containing imidazopyridine substitutes using a three-component reaction is described. This compound was immobilized on magnetic graphene oxide (GO) to make a heterogeneous catalyst for the direct aerobic amidation of benzaldehyde derivatives under solvent-free conditions, as well as the intra-and intermolecular cross dehydrogenative coupling of aldehydes. In addition, the catalytic activity of the NHC catalyst was homogeneously studied in the presence of Fe3O4 nanoparticles under the same conditions, and showed good activity with lower yields than the heterogeneous catalyst.
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.
Synthesis of sterically hindered peptide analogs using diphenyl phosphite as the coupling reagent
Yang, Ting,Lin, Changxue,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
, p. 386 - 392 (2005)
Some model sterically hindered peptide analogs were synthesized with various yields using diphenyl phosphite as the coupling reagent under mild conditions. The experimental procedure is straightforward and the products are easily isolated. This method may be convenient and efficient for the synthesis of hindered peptides.
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.
Synthesis and new application of green and recyclable cyclic poly(L -lactide)-clay hybrid
Prasad, Aitha Vishwa,Biying, Algin Oh,Ling, Woo Yuan,Stubbs, Ludger Paul,Zhu, Yinghuai
, p. 4167 - 4174 (2013)
We report on the application of biodegradable cyclic poly(L-lactide) (PLLA) as new stabilizer; synthesis and application of a cyclic PLLA-clay hybrid material as recyclable catalyst support. Cyclic PLLAs were used to stabilize palladium nanoparticles synthesized by a wet chemical method. It was found that the palladium particles were smaller with cyclic PLLA stabilizer (～5-10 nm) than the particles obtained from linear PLLA. The cyclic PLLA-clay hybrid was prepared by a zwitterionic ring-opening polymerization catalyzed by in situ-generated N-heterocyclic carbene catalyst. Palladium (0) nanoparticles were supported and well dispersed on the cyclic PLLA-clay hybrid to form a new nanocomposite. The nanocomposite was found to be a highly efficient and recyclable catalyst for the aminocarbonylation reactions of aryl halides with various amines.
