- Synthesis of Functionalized Perfluorinated Porphyrins for Improved Spin Switching
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We have established a method to synthesize perfluorinated meso-phenylporphyrins with one phenyl group bearing a substituent in the ortho position. These novel electron-deficient porphyrins are interesting for model enzymes, catalysis, photodynamic therapy, and electron transfer. The key step is the synthesis of an iodine-substituted porphyrin and its Suzuki cross coupling with boronic acid derivatives. We applied the novel strategy to synthesize a highly electron-deficient, azopyridine-substituted Ni-porphyrin that undergoes an improved ligand-driven coordination-induced spin-state switch.
- Dommaschk,N?ther,Herges
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p. 8496 - 8500
(2015/09/15)
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- Baylis-Hillman route to several quinolone antibiotic intermediates
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Treatment of methyl propiolate and 2,4,5-trifluoro-, 2-fluoro-, 2-fluoro-5-methoxy- or 2,3,4,5-tetrafluorobenzaldehydes with a ZrCl 4/Bu4NI combination induces an aldol reaction to furnish β-iodo-α-(hydroxyalkyl)acrylates. These can be used for the preparation of several quinolone intermediates, 1-substituted 4-oxo-1,4-dihydroquinoline-3-carboxylic acids and 9,10-difluoro-3-methyl-2,3- dihydro-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid through the oxidation, amination and hydrolysis reactions. Georg Thieme Verlag Stuttgart.
- Hong, Wan Pyo,Lee, Kee-Jung
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p. 963 - 968
(2007/10/03)
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- Cyclic Organotin Lewis Acids
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The Ph3P=O IR frequency shift method has been used to compare the Lewis acid strength of several cyclic organotin dichlorides.Structures 3, 20, and 4 are relatively weak Lewis acids, less potent than Bu2SnCl2, according to the IR criterion.Steric factors appear largely responsible for the decreased Lewis acidity, altough bond angle strain may also contribute in the case of 3.Introduction of electronegative substituents into the aromatic ring of structures related to 4 results in stronger Lewis acids 8 and 18, both of which are relatively more potent than Ph2SnCl2.Methods for the preparation of precursors to the fluorinated 8 and 18 are described, based on the deprotonation of tetrafluoroaryl precursors.
- Vedejs, E.,Erdman, D. E.,Powell, D. R.
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p. 2840 - 2845
(2007/10/02)
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