10183-82-1Relevant articles and documents
Electrochemically Induced Chain Reactions: The Electrochemical Behavior of Nitrosobenzene in the Presence of Proton Donors in Tetrahydrofuran
Mugnier, Yves,Gard, Jean-Christophe,Huang, Youqin,Couture, Yvon,Lasia, Andrzej,Lessard, Jean
, p. 5329 - 5334 (1993)
The electrochemical reduction of nitrosobenzene in tetrahydrofuran with tetrabutylammonium hexafluorophosphate as the supporting electrolyte and in the presence of fluorene or indene at room temperature gives a mixture of an anil (1 or 3), a nitrone (2 or 4), and azoxybenzene and requires only a catalytic amount of electricity.Lowering the temperature and/or increasing the proportion of proton donor favors the formation of the anil at the expense of the nitrone and azoxybenzene: a 97percent yield of anil 1 was obtained from an electrolysis carried out at -30 deg C using 5 equiv of fluorene.The possible steps of the chain reactions involved are discussed on the basis of electrochemical and chemical data and digital simulation.With phenylacetylene as the proton donor, there is no reaction between nitrosobenzene and phenylacetylene and azoxybenzene is the main product formed.
Insights into the effect of ketylimine, aldimine, and vinylene group attachment and regiosubstitution on the fluorescence deactivation of fluorene
Dufresne, Stephane,Skalski, Thomas,Skene
, p. 173 - 180 (2011)
The spectroscopic and electrochemical properties of a 9-substituted fluorene ketylimine (3) were investigated and compared with those of its vinylene analogue (4) to determine the origins of the quenched fluorescence of these compounds. The predominate mo
Generation and characterization of the selenocysteinyl radical: Direct evidence from time-resolved UV/Vis, electron paramagnetic resonance, and fourier transform infrared spectroscopy
Kolano, Christoph,Bucher, Goetz,Schade, Olaf,Grote, Dirk,Sander, Wolfram
, p. 6609 - 6615 (2005)
The selenocysteinyl radical 1 has been generated for the first time by laser flash photolysis (λexc = 266 nm) of dimethyl bis(N-tert-butoxycarbonyl)-L-selenocystine 2 and of [(9-fluorenylideneamino)- oxycarbonyl]methyl(N-tert-butoxycarbonyl)-L-selenocysteine 3 in acetonitrile and characterized by time-resolved (TR) UV/Vis, Fourier transform infrared (FTIR), and electron paramagnetic spectroscopy in combination with theoretical methods. A detailed product study was conducted using gas chromatography and one- and two-dimensional NMR spectroscopy. In the case of [(9-fluorenylideneamino) oxycarbonyl]methyl(N-tert-butoxycarbonyl)-L-selenocysteine 3, the (9-fluorenylideneamino)oxycarbonyl moiety serves as a photolabile protection group providing a caged selenocysteinyl radical suitable for biophysical applications. Cleavage of the diselenide bridge or the selenium-carbonyl bond by irradiation is possible in high quantum yields. Because of the lack of a good IR chromophore in the mid-IR region, the selenocysteinyl radical 1 cannot be monitored directly by TR FTIR spectroscopy. TR UV/Vis spectroscopy revealed the formation of the selenocysteinyl radical 1 from both precursors. The selenocysteinyl radical 1 has a lifetime τ ≈ 63 μs and exhibits a strong band located at λmax = 335 nm. Calculated UV absorptions of the selenocysteinyl radical (UB3LYP/6-311G(d,p)) are in good agreement with the experimental results. The use of TR UV/Vis spectroscopy permitted the determination of the decay rates of the selenocysteinyl radical in the presence of two quenchers. The product studies demonstrated the reversible photoreaction of dimethyl bis(N-tert-butoxycarbonyl) -L-selenocystine 2. Products of the photolysis of the caged selenocysteinyl radical precursor 3 are dimethyl bis(N-tert- butoxycarbonyl)-L-selenocystine 2, carbon dioxide, and some further smaller fragments. In addition, the photo-decomposition of the (9-fluorenylideneamino) oxycarbonyl moiety produced 9-fluorenone-oxime 4, 9-fluoren-imine 5, and 6 and 7 as products of the dimerization of two 9-fluorenoneiminoxy radicals 8.
Reaction of arynes with trifluoroacetylated β-diketones: Novel formation of isocoumarins and phenanthrenes
Okuma, Kentaro,Tanabe, Yukiko,Fukami, Takuto,Ishibashi, Yuto
, (2018)
Polysubstituted isocoumarins were synthesized by the reaction of substituted 2-(trimethylsilyl)aryl triflates with trifluoromethylated β-diketones in the presence of CsF. The reaction proceeded through carbon-carbon bond insertion of aryne and intramolecular cyclization to form intermediates of alcohol anions, which extruded trifluoromethyl anion to afford isocoumarins. By using CuBr as a catalyst, 2 eq. of aryne reacted with β-diketones to afford phenanthrenes and 1,2-diarylethanones. Although reaction of 2-(trimethylsilyl)phenyl triflate with 1,1,1-trifluoro-4′-methylbenzoylacetone in the presence of CsF gave 3-(4′-methylphenyl)isocoumarin in 67% yield, addition of 0.2 eq. of CuCN resulted in the formation of 9-(4-methylbenzoyl)-10-trifluoromethylphenanthrene in 35% yield.
Selective, Oxophilic Imination of Ketones with Bis(dichloroaluminum) Phenylimide
Eisch, John J.,Sanches, Ramiro
, p. 1848 - 1852 (1986)
Bis(dichloroaluminum) phenylimide, which can be readily prepared from ethylaluminum dichloride and aniline, is shown to be a highly selective iminating agent for aldehydes, ketones, and acid chlorides.Especially the transformation of α,β-unsaturated keton
Bildung von 1,2,4-Trithiolanen in Dreikomponenten-Gemischen aus Phenyl-azid, aromatischen Thioketonen und 2,2,4,4-Tetramethylcyclobutan-thionen: Eine Schwefel-Transfer-Reaktion unter Bildung von 'Thiocarbonyl-thiolaten' ((Alkylidensulfonio)thiolaten) als
Mloston, Grzegorz,Heimgartner, Heinz
, p. 1298 - 1310 (1995)
The reaction of PhN3 and aromatic thioketones 18 (two-component reaction) at 80 degree yields only the corresponding imines 22, S, and N2.Under similar conditions, in the presence of sterically crowded 2,2,4,4-tetramethyl-cyclobutanethiones 19 (three-comp
Photoredox-Catalyzed Synthesis of α-Amino Acid Amides by Imine Carbamoylation
Cardinale, Luana,Schmotz, Mattis-Ole W. S.,Konev, Mikhail O.,Jacobi von Wangelin, Axel
supporting information, p. 506 - 510 (2022/01/20)
An operationally simple protocol for the photocatalytic carbamoylation of imines is reported. Easily available, bench-stable 4-amido Hantzsch ester derivatives serve as precursors to carbamoyl radicals that undergo rapid addition to N-aryl imines. The reaction proceeds under blue light irradiation in the presence of the photocatalyst 3DPAFIPN and Br?nsted/Lewis acid additives. Mechanistic studies indicated a photoredox mechanism that involves carbamoyl radicals.
Photoredox Radical/Polar Crossover Enables Construction of Saturated Nitrogen Heterocycles
Pantaine, Lo?c R.E.,Milligan, John A.,Matsui, Jennifer K.,Kelly, Christopher B.,Molander, Gary A.
supporting information, p. 2317 - 2321 (2019/03/26)
Photoredox-mediated radical/polar crossover (RPC) processes offer new avenues for the synthesis of cyclic molecules. This process has been realized for the construction of medium-sized saturated nitrogen heterocycles. Photocatalytically generated alkyl ra
Preparation method of 10H-spiro[acridine-9,9'-fluorene] and derivative thereof
-
Paragraph 0065-0068, (2019/04/06)
The invention provides a preparation method of 10H-spiro[acridine-9,9'-fluorene] and a derivative thereof, and belongs to the technical field of organic synthesis. According to the invention, an iminecompound, potassium fluoride, 18-corona-6 and methanesu
Structure and Reactivity of Half-Sandwich Rh(+3) and Ir(+3) Carbene Complexes. Catalytic Metathesis of Azobenzene Derivatives
Tindall, Daniel J.,Werlé, Christophe,Goddard, Richard,Philipps, Petra,Farès, Christophe,Fürstner, Alois
supporting information, p. 1884 - 1893 (2018/02/17)
Traditional rhodium carbene chemistry relies on the controlled decomposition of diazo derivatives with [Rh2(OAc)4] or related dinuclear Rh(+2) complexes, whereas the use of other rhodium sources is much less developed. It is now shown that half-sandwich carbene species derived from [Cp?MX2]2 (M = Rh, Ir; X = Cl, Br, I, Cp? = pentamethylcyclopentadienyl) also exhibit favorable application profiles. Interestingly, the anionic ligand X proved to be a critical determinant of reactivity in the case of cyclopropanation, epoxide formation and the previously unknown catalytic metathesis of azobenzene derivatives, whereas the nature of X does not play any significant role in 'OH insertion reactions. This perplexing disparity can be explained on the basis of spectral and crystallographic data of a representative set of carbene complexes of this type, which could be isolated despite their pronounced electrophilicity. Specifically, the donor/acceptor carbene 10a derived from ArC( - N2)COOMe and [Cp?RhCl2]2 undergoes spontaneous 1,2-migratory insertion of the emerging carbene unit into the Rh-Cl bond with formation of the C-metalated rhodium enolate 11. In contrast, the analogous complexes 10b,c derived from [Cp?RhX2]2 (X = Br, I) as well as the iridium species 13 and 14 derived from [Cp?IrCl2]2 are sufficiently stable and allow true carbene reactivity to be harnessed. These complexes are competent intermediates for the catalytic metathesis of azobenzene derivatives, which provides access to α-imino esters that would be difficult to make otherwise. Rather than involving metal nitrenes, the reaction proceeds via aza-ylides that evolve into diaziridines; a metastable compound of this type has been fully characterized.
