588-53-4Relevant academic research and scientific papers
A DFT and experimental study of the spectroscopic and hydrolytic degradation behaviour of some benzylideneanilines
Nelson, Peter N.,Robertson, Tahjna I.
, (2021/10/12)
The spectroscopic and hydrolytic degradation behaviour of some N-benzylideneanilines are investigated experimentally and theoretically via high quality density function theoretical (DFT) modelling techniques. Their absorption and vibrational spectra, accurately predicted by DFT calculations, are highly dependent on the nature of the substituents on the aromatic rings, hence, though some of their spectroscopic features are similar, energetic differences exist due to differences in their electronic structures. Whereas the o-hydroxy aniline derived adducts undergo hydrolysis via two pathways, the most energetically economical of which is initiated by a fast enthalpy driven hydration, over a conservative free energy (ΔG?) barrier of 53 kJ mol?1, prior to the rate limiting entropy controlled lysis step which occurs via a conservative barrier of ca.132 kJ mol?1, all other compounds hydrolyse via a slower two-step pathway, limited by the hydration step. Barriers heights for both pathways are controlled primarily by the structure and hence, stability of the transition states, all of which are cyclic for both pathways.
Microwave assisted synthesis of 4-aminophenol Schiff bases: DFT computations, QSAR/Drug-likeness proprieties and antibacterial screening
Abdelakder, Hellal,Abdellah, Benhamou,Mohamed, Mersellem
, (2021/07/21)
The present work is devoted to the synthesis and study of the structural and electronic properties of three Schiff bases prepared from para-aminophenol under green chemistry conditions. These compounds were successfully synthesized in excellent yields. The synthesized Schiff bases have been characterized by Elemental analysis, FTIR, and NMR (1H and 13C) spectroscopic methods. The molecular geometry, Mulliken atomic charges and vibrational analysis of the studied compounds were investigated theoretically by performing density functional theory (DFT) using the B3LYP/6-31G++(d,p) method. Moreover, these compounds were screened for antibacterial activity. These compounds were found active to be the most active against all the bacteria investigated. The antibacterial activities have been correlated with chemical reactivity parameters and other electronic parameters looking for any relationship between electronic parameters and biological activity. This effort just provides preliminary data for some biological properties. The results are very encouraging, so we can say that these products are biologically active and can be used later in other applications towards drug development.
Tandem imine formationviaauto-hydrogen transfer from alcohols to nitro compounds catalyzed by a nanomagnetically recyclable copper catalyst under solvent-free conditions
Derakhshan, Seyed Ruhollah,Hosseini Moghadam, Hadis,Sansano, José Miguel,Sobhani, Sara
, p. 19121 - 19127 (2021/06/03)
A direct imination reaction was developed by tandem reaction of alcohols and nitro compounds in the presence of Cu-isatin Schiff base-γ-Fe2O3as a nanomagnetically recyclable catalyst under solvent-free conditions. By this method, various imines were prepared in good to high yields from one-pot reaction of various alcohols (primary aromatic and aliphatic) and nitro compounds (aromatic and aliphatic)viaan auto-hydrogen transfer reaction. Use of an inexpensive and easily reusable catalyst, without requiring any additives or excess amounts of benzyl alcohol as the reaction solvent are the other advantages of this method. This catalytic system has the merits of cost effectiveness, environmental benignity, excellent recyclability and good reproducibility.
Additional effect of para-hydroxyl on the reduction potentials of the N-benzylidenebenzenamines
Cao, Chao-Tun,Zhou, Wei,Cao, Chenzhong
, (2019/12/27)
The reduction potential ERed of disubstituted N-benzylidenebenzenamines XArCH NArY (abbreviated as XBAY) is a measure of the electron acceptance ability of the Lowest-energy Unoccupied Molecular Orbital (LUMO) in molecule, which is closely related to the electronic effects of substituents X and Y in molecule. Previous studies on the ERed of XBAY reported by Luo, Wang, and Yuan all did not involve these molecules containing hydroxyl. In this work, 28 samples of disubstituted N-benzylidenebenzenamines containing para-hydroxyl, (abbreviated as 4-OHBAY or XBAOH-4′) were synthesized, and their ERed values were measured. Then, 127 compounds were taken as a complicated ERed data set, which involved 28 compounds (4-OHBAY and XBAOH-4′) of this work and 99 compounds XBAY reported by Luo. Based on these data ERed set, through a quantitative regression analysis method and comparison of the factors affecting the ERed, the following results are obtained: (a) Because the phenolic hydroxyl OH can dissociate H+ to form phenolic oxygen anion, the change regularity of ERed of compounds 4-OHBAY and XBAOH-4′ is somewhat different from that of ERed of XBAY compounds without hydroxyl OH. That is, hydroxyl OH has an additional effect on the ERed, which decreases the ERed value. (b) The additional effects of 4-OH on the ERed is different from that of 4′-OH. The effect of hydroxyl OH attached to the aldehyde aromatic ring on the ERed is more than that of OH attached to the amine aromatic ring.
Synthesis of new cyclotriphosphazene derivatives bearing Schiff bases and their thermal and absorbance properties
Besli, Serap,Do?an, Semih,Mutlu Balci, Ceylan,Tümay, Süreyya O?uz,Ye?i?Lot, Serkan
, p. 31 - 47 (2020/03/25)
In this study, a series of cyclotriphosphazene derivatives containing a Schiff base (3a–3d) were synthesized by the reactions of hexachlorocyclotriphosphazene (1) with bis-aryl Schiff bases (2a–2d) having different terminal groups (H, F, Cl, and Br). The products (3a–3d) were characterized by elemental and mass analyses, FT-IR, and 1 H, 13 C, and 31 P NMR spectroscopies. Furthermore, the structure of compound 3a was also determined by X-ray crystallography. The thermal behaviors and the spectral properties of the new cyclotriphosphazene compounds (3a–3d) were investigated and the results were compared in the series.
Rational Design of Cobalt-Platinum Alloy Decorated Cobalt Nanoparticles for One-Pot Synthesis of Imines from Nitroarenes and Aldehydes
Gong, Wanbing,Han, Miaomiao,Chen, Chun,Lin, Yue,Wang, Guozhong,Zhang, Haimin,Zhao, Huijun
, p. 5948 - 5958 (2020/10/02)
Developing high-performance heterogeneous catalysts for one-pot reductive amination reactions is critically important for pharmaceutical and agrochemical synthetic industries. In this work, N-doped carbon nanotubes supported CoPt alloy decorated Co nanoparticles (NPs) are successfully fabricated. As a consequence, the resultant catalyst exhibits desirable activity, selectivity and stability toward the one-pot synthesis of imines. More importantly, the extensive experimental studies and density function theory (DFT) calculations results reveal that the high catalytic activity of the catalyst is mainly due to the co-existence of CoPt alloy NPs and Co NPs with Co?Nx active sites. The high selectivity of imines could be ascribed to the following aspects: (1) competitively preferred adsorption of nitroarenes to avoid side-hydrogenation of aldehydes; (2) weakened adsorption of imines to minimize its over-hydrogenation. This work may provide a promising direction and strategy to design high-performance reductive amination catalysts for industrial applications.
Chemoselective Reduction of the P=O Bond in the Presence of P–O and P–N Bonds in Phosphonate and Phosphinate Derivatives
Sowa, Sylwia,Pietrusiewicz, K. Micha?
supporting information, p. 923 - 938 (2019/01/22)
Chemoselective reduction of the strong P=O bond in the presence of weaker P–O (ester) and P–N (amide) bonds in phosphonic acid derivatives has constituted an unresolved problem in organophosphorus chemistry for years. This long-standing problem is now solved for biologically relevant α-hydroxy and α-amino phosphonic as well as phosphinic acids esters and amides. The reduction of the P=O bond without concomitant scission of the ester and amide bonds is affected by use of BH3, a mild reducing agent, which affords the corresponding borane protected PIII phosphonite and phosphinite derivatives in one step. A mechanistic rationale is proposed for the role played by neighboring OH and NHR groups in facilitating the reduction, and for the observed chemo- and stereoselectivity. The reduction methodology described opens previously unavailable synthetic options in chemistry of α-functionalized phosphonic and phosphinic acids by offering a unique possibility for direct modifications of oxidation level of the P-center in these compounds.
Effect of substituents on the UV spectra of supermolecular system: Silver nanoparticles with bi-aryl Schiff bases containing hydroxyl
Cao, Chao-Tun,Cheng, Shimao,Zhang, Jingyuan,Cao, Chenzhong
, (2018/11/25)
Effect of substituents on the ultraviolet (UV) spectra of supermolecular system involving silver nanoparticles (AgNPs) and Schiff bases was investigated. AgNPs and 49 samples of model compounds (MC), bi-aryl Schiff bases containing hydroxyl (XBAY, involving 4-OHArCH?NArY, 2-OHArCH?NArY, XArCH?NAr-4′-OH, and XArCH?NAr-2′-OH), were synthesized. The size of AgNPs was characterized by transmission electron microscopy (TEM), and the UV absorption spectra of AgNPs, XBAYs, and MC-AgNPs mixed solutions were measured, respectively. The results show that (1) the size of AgNPs is larger in MC-AgNPs solutions than that in AgNPs solution due to the distribution of MC molecules on the surface of AgNPs; (2) the UV absorption wavelength of XBAYs changes in the action of AgNPs and their wavelength shift exists limitation between XBAY and MC-AgNPs solutions; and (3) the wavelength shift limit of MC-AgNPs (λWSL) is influenced by the substituents X and Y and the position of hydroxyl OH. The wavenumber ΔνWSL of λWSL can be quantified by employing the excited-state substituent constant σexCC and Hammett constant σ of substituents X and Y. Comparing with the 4-OH, the 4′-OH makes the ΔνWSL a red shift, whereas the 2′-OH, comparing with the 2-OH, makes the ΔνWSL a blue shift.
A new bifunctional heterogeneous nanocatalyst for one-pot reduction-Schiff base condensation and reduction-carbonylation of nitroarenes
Sobhani, Sara,Chahkamali, Farhad Omarzehi,Sansano, José Miguel
, p. 1362 - 1372 (2019/01/24)
In this work, synthesis of Pd-NHC-γ-Fe2O3-n-butyl-SO3H and its activity as a bifunctional heterogeneous nanocatalyst containing Pd-NHC and acidic functional groups, are described. This newly synthesized nanomagnetic catalyst is fully characterized by different methods such as FT-IR, XPS, TEM, VSM, ICP and TG analysis. At first, the catalytic activity of Pd-NHC-γ-Fe2O3-n-butyl-SO3H is evaluated for the reduction of nitroarenes in aqueous media using NaBH4 as a clean source of hydrogen generation at ambient temperature. Using the promising results obtained from the nitroarene reduction, this catalytic system is used for two one-pot protocols including reduction-Schiff base condensation and reduction-carbonylation of various nitroarenes. In these reactions the in situ formed amines are further reacted with aldehydes to yield imines or carbonylated to amides. The desired products are obtained in good to high yields in the presence of Pd-NHC-γ-Fe2O3-n-butyl-SO3H as a bifunctional catalyst. The catalyst is reused with the aid of a magnetic bar for up to six consecutive cycles without any drastic loss of its catalytic activity.
One-pot solvothermal synthesized CoS2@MoS2 nanocomposites for selective reduction coupling reaction to synthesize imines
Han, Wenpeng,Wang, Junwei,Li, Xuekuan,Zhou, Ligong,Yang, Ying,Tang, Mingxing,Ge, Hui
, p. 86 - 91 (2019/03/14)
Selective reduction coupling of nitroaromatics and aldehydes for imines synthesis has been investigated by using a series of bifunctional CoS2@MoS2 catalysts prepared by one-pot solvothermal method. Under optimal Co/Mo ratio of 0.75 and preparation temperature (180 °C), CoS2@MoS2–180-0.75 catalyst shows 96.5% nitrobenzene conversion, 93.0% imine selectivity and good versatility for substituted nitrobenzene and different aldehydes under mild conditions (60 °C, 1.5 MPa H2). The characterizations reveal that high nitroaromatics hydrogenation activity and good selectivity are mainly due to the formation of CoMoS phase, the coupling reaction between aniline derivatives and aldehydes is achieved by the appropriate acidity of CoS2@MoS2 nanocomposites.
