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All total 11 Articles be found
All total 11 Articles be foundInter-Ring Torsions in N-Phenylmaleimide and Its o-Halo Derivatives: An Experimental and Computational Study
Miller, Christopher W.,Hoyle, Charles E.,Valente, Edward J.,Magers, David H.,Joensson, E. Sonny
, p. 6406 - 6412 (1999)
Structures of N-phenylmaleimide and its o-halophenyl derivatives have been determined in the solid state and show the angle between the phenyl and pyrolinyl ring planes to vary from 49.5° to 83.9° with increasing values for compounds with the larger ortho halophenyl substituents (H F ≤ Cl ≤ Br I). Experimental torsions and trends in the series are supported by semiempirical AM1 and ab initio SCF, DFT, and MP2 calculations. Calculations (AM1) on N-phenylmaleimide modeling the torsional deformation between the rings show that the barrier to planarity has a lower energy than that through a perpendicular conformation. In its o-halo derivatives, molecular planarity is not possible, and torsional deformation proceeds through the perpendicular conformation with diminishing, possibly vanishing, barriers with increasing halogen size. For chloro, bromo, and iodo derivatives, twisted ground-state molecular conformations reside in broad minima essentially centered around the perpendicular conformations. The unusually strong, longer wavelength electronic bands observed in the solution spectra of the series were modeled by Zindo/S CIS computations at the optimum AM1 molecular geometries. The observed lower energy (285-305 nm) band for the parent through the o-bromo derivative appears to arise from a {n(O,N); π (phenyl)} → π*(maleimide) transition. The next higher energy (250-285 nm) band appears to be essentially a phenyl π Ρ π* transition. In the o-iodo derivative, a phenyl π → * (C-I) transition appears to contribute to the longer wavelength band. Trends in the observed electronic spectra in acetonitrile within the series of compounds accord roughly with the results of the computations.
Catalyst and Additive-Free Diastereoselective 1,3-Dipolar Cycloaddition of Quinolinium Imides with Olefins, Maleimides, and Benzynes: Direct Access to Fused N,N′-Heterocycles with Promising Activity against a Drug-Resistant Malaria Parasite
Kumar, Rakesh,Chaudhary, Sandeep,Kumar, Rohit,Upadhyay, Pooja,Sahal, Dinkar,Sharma, Upendra
, p. 11552 - 11570 (2018/09/25)
A convenient and eco-friendly synthesis of various fused N-heterocyclic compounds through catalyst and additive-free 1,3 dipolar cycloadditions of quinolinium imides with olefins, maleimides, and benzynes in excellent yields and diastereoselectivities is reported. The thermally controlled diastereoselective [3 + 2] cycloaddition reaction between quinolinium imides and olefins provided cis-isomers at low temperature and trans-isomers at high temperature. A reaction between quinolinium imides with substituted maleimides gave four-ring-fused N-heterocyclic compounds in high yields as a single diastereomer. The aryne precursors also provided four-ring-fused N,N′-heterocyclic compounds in high yields. The in vitro antiplasmodial activity of selected molecules revealed that this class of molecules possesses potential for ongoing studies against malaria.
Potent Nematicidal Activity of Maleimide Derivatives on Meloidogyne incognita
Eloh, Kodjo,Demurtas, Monica,Mura, Manuel Giacomo,Deplano, Alessandro,Onnis, Valentina,Sasanelli, Nicola,Maxia, Andrea,Caboni, Pierluigi
, p. 4876 - 4881 (2016/07/06)
Different maleimide derivatives were synthesized and assayed for their in vitro activity on the soil inhabiting, plant-parasitic nematode Meloidogyne incognita, also known as root-knot nematode. The compounds maleimide, N-ethylmaleimide, N-isopropylmaleimide, and N-isobutylmaleimide showed the strongest nematicidal activity on the second stage juveniles of the root-knot nematode with EC50/72h values of 2.6 ± 1.3, 5.1 ± 3.4, 16.2 ± 5.4, and 19.0 ± 9.0 mg/L, respectively. We also determined the nematicidal activity of copper sulfate, finding an EC50 value of 48.6 ± 29.8 mg/L. When maleimide at 1 mg/L was tested in combination with copper sulfate at 50 mg/L, we observed 100% mortality of the nematodes. We performed a GC-MS metabolomics analysis after treating nematodes with maleimide at 8 mg/L for 24 h. This analysis revealed altered fatty acids and diglyceride metabolites such as oleic acid, palmitic acid, and 1-monopalmitin. Our results suggest that maleimide may be used as a new interesting building block for developing new nematicides in combination with copper salts.
