查看更多>>摘要：The complex [dippeNi(COD)] (dippe = 1,2-bis(diisopropyl phosphino)ethane) was used as a catalytic precursor in furfural (FF) and 5-(hydroxymethyl)furfural (HMF) valorization, along with formic acid as hydrogen transfer agent, to produce the corresponding alcohol in each case, with excellent yields (>= 99%) and under mild conditions (5 h, 120 degrees C). The air-stable Ni(II)-catalyst precursor, [dippeNiCl(2)], was assessed in FF hydroamination, with a variety of anilines, using FA as hydrogen source (at 16 h and 120 degrees C), to produce furfuryl amines with an excellent yield and selectivity (89 to >99%). To our knowledge, this is the first report of reductive amination of FF to get furfuryl amines using a homogeneous Ni catalyst in a hydrogen transfer protocol. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：The present review, which includes a description of modern achievements in the field of synthesis methods, the study of structural features and the possibility of practical use of organometallic compounds of bismuth, is based on an analysis of the literature published for the period from 2010 to 2020. Some of the earlier works are presented in the review because of their importance. The bibliography includes 100 references. (c) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：Ammonium perchlorate (AP) is the primary oxygen source for solid propellants; its thermal decomposition behavior is determinant for the overall performance of the ensuing propellant. In this perspective, a novel Intermittent, Spray Coating, Draying, and Mixing (ISCDM) method is introduced herein to prepare AP@CuO, PA@GO, and AP@CuO@GO core-shell composites. The as-synthesized materials morphological information, crystalline structure, and elemental composition are probed by powder X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The as-prepared CuO nanospheres were effectively embedded into the AP microparticles surface. AP@CuO microparticles were continuously coated with graphene oxide (GO) nanosheets. Particle size analyzer was used to probe the particle size distribution of core-shell composites. Results show that the application of ISCDM method results in a typical narrow gaussian size distribution with an average diameter of hundred microns ranking from 158.56 mu m to 166.22 mu m. The thermal decomposition and the catalytic performances were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). AP@CuO@GO core-shell composite exhibits an excellent thermal decomposition behavior: a low thermal decomposition temperature (LTD) of 337 degrees C, reduced values of the High thermal decomposition temperature HTD to be overlapped with the LTD step, and a significant energy release of 1543 J g(-1) are registered. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：1,1'-Bis(diphenylphosphino)ferrocene (dppf) and structurally related ferrocene bis-phosphines are indispensable ligands for coordination chemistry and catalysis. This contribution focuses on the coordination behaviour and catalytic properties of two dppf congeners bearing 1,3,5,7-tetramethy1-2,4,6-trioxa8-phosphatricyclo[3.3.1.1 (3,7)]decane-8-yl groups (CgP) as the P-donor moieties, viz. Ph(2)PfcCgP (1) and its semi-homologous counterpart Ph(2)PfcCH(2)CgP (2; fc = ferrocene-1,1'-diyl). In reactions with a PdCl2 source, compound 1 produced exclusively the cis-chelate complex [PdCl2 (1-K-2 P,P')], while the homologated ligand 2 afforded a complex mixture of compounds which equilibrated upon heating in methanol in favour of the symmetrical dimeric complex trans-[(mu-2)PdCl2](2) as a mixture of racemic and meso isomers. Notably, in aqueous Pd-catalysed cyanation of aryl bromides and Suzuki-Miyaura-type cross-coupling of benzoyl chlorides with boronic acids producing benzophenones, catalysts generated in situ from bis-phosphine 1 and Pd(II) sources were often more active than their counterparts resulting from dppf and 2. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：The tridentate S (O) under barS-coordinating ligand O(2,3-Me3SiC6H3SH)(2) (1) was obtained through selective ortholithiation of O(2-C6H4SH)(2) followed by silylation with Me3SiCl. The ligands O(2,3-Me3SiC6H3SH)(2) (1) and MeN(2-C6H4SH)(2) (2) react with SiHal(4) (Hal = Cl, Br) and Et3N in toluene to give the bis-ligated complex [O(2,3-Me3SiC6H4S)(2)](2)Si ( 3), the mono-ligated complexes [O(2,3-Me3SiC6H3S)(2)]SiCl2 (4), [MeN(2-C6H4S)(2)]SiCl2 (5), and [MeN(2-C6H4S)(2)]SiBr2 (6). The structure of 4 was established by single crystal X-ray diffraction analysis, indicating presence of hypercoordinted Si(IV) atom with [S (O) under barS]SiCl2 polyhedron. The complexes 4 and 6 were reduced by KC8 to highly reactive Si(II) derivatives, which were detected by MALDI-TOF mass spectrometry as the insertion products into CH3I and THF. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：Graphene oxide (GO) was functionalized with two organic ligands, triethylenetetramine (TETA) or 2,6-diaminopyridine (DAP), followed by palladium nanoparticles (Pd NPs) for the synthesis of Pd NPs/GO-TETA and Pd NPs/GO-DAP nanocomposites, respectively. The two heterogeneous nanocomposites were fully characterized and their efficiency was investigated for C-C bond formation for the synthesis of biaryl compounds via the Suzuki cross-coupling reaction of aryl halides with arylboronic acid derivatives. The obtained results indicated that the Pd NPs/GO-TETA nanocomposite was more effective in the Suzuki coupling reaction as compared to Pd NPs/GO-DAP. Thus, the Suzuki cross-coupling reaction of different aryl halides with arylboronic acid derivatives using Pd NPs/GO-TETA nanocomposite catalyst in the presence of Na2CO3 as base in DMF/H2O (1 /1) as solvent at 90 degrees C was carried out to afford the desired biaryl compounds in high to excellent yields (81-100%) and short reaction times (10-90 min). Additionally, Pd NPs/GO-TETA nanocomposite can be recovered and reused for 8 consecutive runs without any apparent loss of its catalytic activity, proving its high stability and potential use in organic transformations. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：The 8-aminoquinoline (8AQ) drug Primaquine (PQ) is a prime anti-malarial drug, used in the treatment of malaria due to plasmodium vivax and plasmodium ovale. The hydroxylated metabolite of Primaquine is also responsible for many essential sexual transmission stages of Plasmodium falciparum. Present work reported the hydroxylation of Primaquine at ortho (2PQ) and para (4PQ) position by Cytochrome P450 enzyme. Density functional theory (DFT) is used to investigate the underlying pathway for aromatic hydroxylation at ortho (2PQ) and para (4PQ) position to produce 2-hydroxylated and 4-hydroxylated Primaquine respectively. Truncated model of putative active oxidant i.e. ferryl oxo porphyrin cation radical [Fe-IV(O)(heme(+))], which is referred as Cpd I in Cytochrome P450 enzymes has been used to mimic the behavior of enzyme. Substrate was modelled and reaction mechanism for two degenerate spin states namely doublet and quartet were performed to dwell the overall potential energy landscape, along with electronic structure and properties of reactant complex (RC), transition states (TS), intermediates (IM) and product complex (PC). The reaction was stepwise with electrophillic addition as the rate determining step, spin selectivity product formation was observed for hydroxylated product formation on high spin (HS) surface. All calculations are done for isolated reaction coordinate. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：In this paper we report a novel and straightforward method for the synthesis of alpha-amino phosphonates via three-component reaction of amines, aldehydes, and triethyl phosphite in the presence of Cu-2(BDC)(2) DABCO (Cu-MOF) as a recyclable heterogeneous catalyst. The chemical structures of the all synthesized compounds were confirmed by NMR, IR and CHN analysis. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：A highly regio- and stereoselective sulfonylation of allenes was developed that provided direct access to alpha, beta-substituted unsaturated sulfone. By means of visible-light photoredox catalysis, the free radicals produced by p-toluenesulfonic acid reacted with multisubstituted allenes to obtain Markovnikov-type vinyl sulfones with Ru(bpy)(3)Cl-2 or Rhodamine B as photocatalyst. The yield of this reaction could reach up to 91%. A series of unsaturated sulfones would be used for further transformation to some valuable compounds. (C) 2021 Elsevier B.V. All rights reserved.
Rostami, Mohammad SaeidKhodaei, Mohammad MehdiRostami, Safdar
13页
查看更多>>摘要：Water is the most abundant and most essential substance for health and human life. Unfortunately, over the past years, with the development of industries and factories, the pollution caused by their output in the water environment has increased. The existence of heavy metal ions and artificial dyes in water due to their high toxicity, in addition to environmental pollution, are also dangerous to human health. Therefore, it is necessary to provide an easy and efficient method for the decomposition of pollution from the water environment. So far, various methods (oxidation, reverse osmosis, ion exchange, adsorption, etc.) have been investigated to remove contaminants from the water media. Among all these, absorption as an effective and low-cost method has always been considered by researchers in recent years. Polymer nanocomposites (PNCs) have been highly acclaimed by researchers due to their diverse synthetic methods and high adsorption capacity in removing contaminants. Herein, we review the adsorption of Cd2+ and Methylene blue (MB) dye from an aqueous solution using various PNCs reinforced with multi-walled carbon nanotubes (MWCNT)s. Experimental results and study of Langmuir and Freundlich isotherm models indicate high adsorption capacity by these NCs. (C) 2021 Elsevier B.V. All rights reserved.
NSTL
Elsevier