889-29-2Relevant academic research and scientific papers
Conformation and structure of 3-methoxyphenyl-salicylaldimine
Elmali,Kabak,Elerman
, p. 229 - 234 (1999)
3-methoxyphenyl-salicylaldimine (C14H13NO2) was studied by X-ray analysis and AM1 molecular orbital methods. It crystallises in the monoclinic space group P21/c with a = 20.486(4) A, b = 4.7935(8) A A, c = 12.310(5) A, β = 107.43(2)°, V = 1153.3(6) A3, Z = 4, D0 = 1.309 g cm-3, Z = 4, and μ(MoK(α)) = 0.088 mm-1. The structure was solved by direct methods and refined to R = 0.033 for 1635 reflections [I 1(C8-N1-C7-C6), θ2(N1-C7-C6-C5), and θ3(C9-C8-N1-C7) varied every 10°. The theoretical calculations were carried out to compare with experimental results of the molecular conformations. The optimized geometry of the crystal structure corresponding to a non-planar conformation is the most stable conformation in all theoretical calculations.
Copper-Catalyzed Asymmetric Annulation Reactions of Carbenes with 2-Iminyl- or 2-Acyl-Substituted Phenols: Convenient Access to Enantioenriched 2,3-Dihydrobenzofurans
Liang, Xin-Shen,Li, Rui-Dong,Wang, Xiao-Chen
supporting information, p. 13885 - 13889 (2019/08/26)
We have developed a method for the highly diastereo- and enantioselective construction of 2,3-dihydrobenzofurans bearing tetrasubstituted carbon stereocenters by means of annulation reactions between carbenes and 2-iminyl- or 2-acyl-substituted phenols through catalysis by readily accessible copper(I)/bisoxazoline catalysts under mild conditions. These reactions feature a unique mechanism in which the copper catalyst serves a dual function: first it reacts with the diazo compound to generate a metal carbene, and second, upon formation of an oxonium ylide, it acts as a Lewis acid to activate the imine or ketone for diastereo- and enantioselective cyclization.
Abnormal effect of hydroxyl on the longest wavelength maximum in ultraviolet absorption spectra for bis-aryl Schiff bases
Cao, Chao-Tun,Zhou, Wei,Cao, Chenzhong
, (2017/09/19)
Two sets of bis-aryl Schiff bases that contain 4(or 4′)-OH and 2(or 2′)-OH were synthesized. The first set consists of 4-HOArCH=NArY and XArCH=NArOH-4′, and the second set consists of 2-HOArCH=NArY and XArCH=NArOH-2′. Their ultraviolet absorption spectra were measured and investigated. A very interesting phenomenon was observed by analyzing their wave number νmax (cm?1) of longest wavelength maximum λmax (nm) of ultraviolet. Compared with the change regularity of the νmax of XArCH=NArY (where the X and Y excluded OH), the 4′-position hydroxyl (4′-OH) and 2′-position hydroxyl (2′-OH) have abnormal performance. The details are the following: the 4′-OH contributes an additional red shift to the νmax of XArCH=NArOH-4′ (λmax increase), whereas the 2′-OH contributes an additional blue shift to the νmax of XArCH=NArOH-2′ (λmax decrease). In addition, there are ortho steric effects of all 2-OH and 2′-OH on the νmax for 2-HOArCH=NArY and XArCH=NArOH-2′, and the ortho steric effect contributes a red shift to their νmax. These experimental facts can provide an important theoretical reference for us using aryl Schiff base compounds as optical materials and performing the molecular design.
Synthesis, antioxidant and antibacterial activities of some Schiff bases containing hydroxyl and methoxy groups
Al-Mamary, Mohammed,Abdelwahab, Siddig Ibrahim,Ali, Hapipah Mohd,Ismail, Salma,Abdulla, Mahmood Ameen,Darvish, Pouya
experimental part, p. 4335 - 4339 (2012/09/07)
A series of Schiff bases were synthesized from different aromatic amines and aromatic aldehydes containing hydroxyl and methoxy groups. These compounds were characterized by IR and 1H NMR. All the compounds were screened for in vitro antioxidant activity using DPPH method and total reducing power activity based on the ability of compounds to reduce the Fe3+-TPTZ complex to the Fe2+/ferrous. Compounds substituted with hydroxyl and other electron donating groups, such as, methoxy groups showed low to high antioxidant activity. In addition, the compounds have been screened for their antibacterial activity against strains of Escherichia coli, Methycillinresistant Staphylococcus aureus, Klebsiella pneumonia and Pseudomonas aeruginosa. The tested Schiff bases at 5 mg/disc showed different antibacterial activities depending on the type of the tested bacterial species. However, E. coli appeared to be sensitive to seven compounds (Ia, Ib, Ic, Id, If, IIb and IIe), while methicillin resistant Staphylococcus aureus (MRSA) was affected by Ic, Ie, IIc and IIe compound. On the other hand, the compounds Ia, Ic, Id, Ie and IIh revealed antibacterial activity against Klebsiella spp. The Pseudomonas aeruginosa was not sensitive to any of the tested Schiff bases.
N-Substituted Salicylaldimines Derivatives of Germanium(IV)
Singh, R. V.,Tandon, J. P.
, p. 1391 - 1398 (2007/10/02)
Hexa-coordinated Schiff base complexes of germanium of the general type Ge(OC2H5)2(SB)2 (SB(-) is the anion of the monofunctional bidentate Schiff base, SBH) have been synthesized by the reaction between ethyl-orthogermanate and the Schiff base in benzene
