查看更多>>摘要：In this study, new coordination complexes (1a-1e) of Pd(II) with Schiff base ligands were synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductivity, FT-IR, H-1-C-13 NMR spectroscopy, UV-vis spectroscopy, and mass spectrometry techniques. The ligands formed only 1:2 complexes with the Pd(II) except for the complex 1e . The thermal analysis of the complexes was performed by the TGA technique. The antioxidant potential, enzyme inhibition activity, and catalytic properties of the complexes were investigated as well. The Pd(II) complexes 1b and 1c indicated the best catalytic activity with 62.63% and 61.05% selectivity in the conversions of 82.61% and 87.84%. The in vitro antioxidant activity showed that the Pd(II) complexes, particularly 1a and 1e have effective antioxidant activities. According to the enzyme activity analyses, complex 1b (IC50 value 69.3 +/- 5.2 mu M) showed the most effective pancreatic lipase inhibition, whereas complex 1e (IC50 value 25.7 +/- 3.2 mu M) had the most effective tyrosinase inhibition among the synthesized compounds. Overall, the present paper discusses the synthesis, characterization and catalytic activities of various novel Pd(II)-Schiff base complexes with their antioxidant potentials, pancreatic lipase and tyrosinase inhibitory activities. (C)& nbsp;2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Merck developed and launched DOZN (TM) 2.0, a unique web-based greener alternative scoring matrix, also known as a quantitative green chemistry evaluator, based on the 12 principles of green chemistry for researcherss to evaluate relative greenness of products/processes. The 12 principles of green chemistry provide a framework for learning about green chemistry and designing or improving materials, products, processes, and systems. DOZN (TM) 2.0 scores products based on metrics for each principle and aggregates principle scores to derive a final aggregate score. The system calculates scores based on manufacturing information, Globally Harmonized System (GHS), and Safety Data Sheets (SDS) data which provide the green score for products/processes. DOZN (TM) 2.0 is flexible enough to encompass the diverse portfolio of products ranging from chemistry to biology to material science-based products. The DOZN (TM) 2.0 system has also been verified and validated by a third party to ensure best practices are applied. This new Greener Chemistry Initiative offers users an increased breadth of Greener Alternative products with confirmatory documentation to validate greener characteristics. Through DOZN (TM) 2.0 customers now have access to calculate the green scores of their processes and products. This free, web-based tool provides users with even more data so that they are properly equipped to increase their sustainability. (c) 2022 Published by Elsevier B.V.
Al-Marhabi, Aisha R.El-Shishtawy, Reda M.Al-Footy, Khalid O.
8页
查看更多>>摘要：Pinacol boronate esters D1-D3 derived from phenothiazine (PTZ), phenoxazine (POZ), and carbazole (CZ), having a tolyl moiety as an auxiliary donor and 2-ethylhexyl as a branched alkyl chain to prevent the molecular aggregation have been synthesized and characterized. Thus, the N-alkylation of PTZ, POZ, and CZ followed by bromination afforded the corresponding products in good yield. These compounds were C -C coupled via the Suzuki coupling reaction with tolylboronic acid and then underwent the Miyaura borylation reaction to get the key electron donors D1-D3. The chemical structures of all compounds were confirmed by spectral data (IR, 1 H NMR, 13 C NMR, 11 B-NMR, and HRMS). The UV-vis absorption and fluorescence characteristics of D1-D3 compared with their cores PTZ, POZ and CZ in THF solution have been investigated. The results indicated a red-shift in both absorption and fluorescence of D1-D3 , indicating that the tolyl moiety increased the conjugation of the donor cores. A huge Stokes shift ranging from 15,0 0 0 to 17,0 0 0 cm -1 was observed for D1-D3 intermediates. The newly synthesized boronate key electron donors have the potential to construct optoelectronic materials. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The mechanisms of nickel-catalyzed cyanation of aryl halides with 2-methyl-2-phenylmalononitrile (MPMN) through the reductive-coupling reactions have been investigated using density functional theory (DFT) calculations. The Ni I catalytic cycle was more favored over the Ni degrees catalytic cycle. The results showed that the overall catalytic cycle included the oxidative addition, reduction, 1,2-migratory insertion, beta-C elimination, product separation and catalyst regeneration steps. We calculated the high spin state of triplet Ni catalytic cycle and the low spin state of singlet Ni catalytic cycle. The results showed that the rate-determining step in the whole catalytic cycle was the oxidative addition step where the Gibbs free energy barrier AG sol in N,N-dimethylacetamide (DMA) solution is 14.8 kcal/mol, which kept consistent with the experimental results.
Bruno, Sofia M.Pillinger, MartynValente, Anabela A.Goncalves, Isabel S....
7页
查看更多>>摘要：Campholenic aldehyde (CPA), an important flavor and fragrance intermediate, can be obtained by the Lewis acid-catalyzed isomerization of alpha-pinene oxide (PinOx), although achieving high yields ( > 90%) is a difficult challenge due to the high reactivity of the epoxide. In the present work, indenyl-molybdenum(II)bipyridine complexes [IndMo(bipy R )(CO) 2 ](BF 4 ) (bipy R = 2,2 ' -bipyridine (R = H ) or 4,4 ' -disubstituted2,2 ' -bipyridine) have been combined with various ionic liquid solvents to develop an efficient process for the selective conversion of PinOx to CPA under mild (35 degrees C) conditions. Excellent CPA yields (95%) were repeatedly obtained within 1 min reaction time for the easily recyclable catalytic system comprising [IndMo(4,4 ' -dinonyl-2,2 ' -bipyridine)(CO) 2 ](BF 4 ) and choline bis(trifluoromethylsulfonyl)imide.(c) 2022 Elsevier B.V. All rights reserved.
Gholinejad, MohammadShojafar, MohammadSansano, Jose M.Mikhaylov, Vladimir N....
14页
查看更多>>摘要：A new nitrogen-rich hyperbranched polymer comprising imidazolium and triazole moieties used for stabilization of Pd nanoparticles. The resulting new material, PolyTZ-IL@Pd NPs, was characterized with different techniques including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-Ray (EDX), and transmission electron microscopy (TEM) analysis. PolyTZ-IL@Pd NPs has been used as an efficient catalyst in the reduction of nitroarenes to amines and cyanation of aryl bromides and iodides. The catalyst showed high stability and recyclability and recycled at least 10 times in reduction of 1-chloro-4-nitrobenzene and 5 times in cyanation of iodobenzene. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：New dinuclear o -phenylene linked bis(amidinate) rare-earth metal alkyl complexes [{C 6 H 4 -1,2(NC t BuNC 6 H 5 ) 2 }RECH 2 SiMe 3 ] 2 (RE = Y ( 1 ), Er ( 2 ), Yb ( 3 )) were synthesized in high yields. All complexes were established by single-crystal X-ray diffraction studies, which revealed that each bis(amidinate) ligand linked to two metal ions with one amidinate group coordinated to the metal ion in classical K2 - N,N' modes, while the other amidinate group worked as a bridge coordination with the two metal ions in it- K2 : K1 chelating mode, resulting in the formation of amidinate group bridged dinuclear complexes. The complexes exhibited excellent catalytic reactivity for the Strecker reaction with wide range of unactivated imines under solvent-free conditions in presence of 1.0 mol% catalyst loading. (c) 2022 Elsevier B.V. All rights reserved.
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