51792-85-9Relevant articles and documents
Substituent effects on the electronic structure of the flat Blatter radical: Correlation analysis of experimental and computational data
Bartos, Paulina,Chrostowska, Anna,Hande, Aniket A.,Kaszyński, Piotr,Pietrzak, Anna
, p. 22876 - 22887 (2021/12/24)
A series of C(10)-substituted derivatives of 2-Ph-3H-[1,2,4]triazino[5,6,1-kl]phenoxazin-3-yl was obtained using the aza-Pschorr, photochemical and radical-induced cyclization reactions, and through functional group transformations of the C(10)-amino and C(10)-iodo derivatives. The iodo derivative underwent Pd-catalyzed C-C cross coupling reactions leading to the installation of Ph, 2-thienyl and PhCC groups at the C(10) position effectively extending electronic conjugation. The substituent effect on the electronic properties of the 3H-[1,2,4]triazino[5,6,1-kl]phenoxazin-3-yl was investigated in twenty one derivatives with a diverse range of functional groups by spectroscopic (UV-vis and EPR) and electrochemical methods augmented with DFT calculations. Results show that the lowest energy electronic absorption and redox potentials correlate well with the σp substituent parameter, while aN hfcc and the N-H bond dissociation energy (BDE) are well described by the σm parameter. In general, increasing the electron donating ability of the C(10)-X substituent lowers the π-π?(1) excitation energy, cathodically shifts the redox potentials, increases spin delocalization beyond the [1,2,4]triazinyl ring and lowers BDE. The latter two parameters are important indicators of the overall radical stability. Molecular and crystal structures of three radicals were established with the single crystal XRD method. This journal is
Direct nitration method of electron-enriched aromatic hydrocarbons
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Paragraph 0063-0065, (2018/10/02)
The invention discloses a direct nitration method of electron-enriched aromatic hydrocarbons, and belongs to the field of organic synthesis. The direct nitration method is a novel green free radical nitration method; aromatic hydrocarbons are taken as raw materials, acetonitrile, dichloromethane, chloroform, or acetone is taken as a reaction solvent, at room temperature conditions, the raw materials and green nitration reagent tert-butyl nitrite (TBN) are subjected to free radical nitration so as to obtain nitro-aromatic compounds. According to the direct nitration method, no metal is adoptedin reaction, tert-butyl nitrite is directly adopted in nitration reaction. Electron-donating groups such as OMe are introduced, the electron density of aromatic compounds is increased, the nitration reaction possibility is increased. The using amount of tert-butyl nitrite is reduced; only a product and tert-butyl alcohol are generated, environment pollution is reduced. The direct nitration methodis promising in application prospect in the field of nitro-aromatic compound synthesis, green nitration is realized, and a novel idea is provided for large-scale industrialized nitro-aromatic compoundproduction.
Synthesis of an azido-tagged low affinity ratiometric calcium sensor
Caldwell, Stuart T.,Cairns, Andrew G.,Olson, Marnie,Chalmers, Susan,Sandison, Mairi,Mullen, William,McCarron, John G.,Hartley, Richard C.
, p. 9571 - 9578 (2015/12/01)
Changes in high localised concentrations of Ca2+ ions are fundamental to cell signalling. The synthesis of a dual excitation, ratiometric calcium ion sensor with a Kd of 90 μM, is described. It is tagged with an azido group for bioconjugation, and absorbs in the blue/green and emits in the red region of the visible spectrum with a large Stokes shift. The binding modulating nitro group is introduced to the BAPTA core prior to construction of a benzofuran-2-yl carboxaldehyde by an allylation-oxidation-cyclisation sequence, which is followed by condensation with an azido-tagged thiohydantoin. The thiohydantoin unit has to be protected with an acetoxymethyl (AM) caging group to allow CuAAC click reaction and incorporation of the KDEL peptide endoplasmic reticulum (ER) retention sequence.
