54600-85-0Relevant academic research and scientific papers
Diindenopyrazines: Electron-Deficient Arenes
Brosius, Victor,Bunz, Uwe H. F.,Freudenberg, Jan,Hippchen, Nikolai,Rominger, Frank,Weigold, Svenja
supporting information, p. 10001 - 10005 (2021/06/07)
The syntheses, properties and application of the air-stable electron acceptors, diindenopyrazines 4 a–g are reported demonstrating the introduction of functional aryl groups in the 6- and 12-positions. The targets are accessible on the hundred milligram to gram scale. The structure of the aryl groups in 4 a–g modulates their solubility, redox potentials and optical properties. The introduction of electron-poor aryl groups to the electron-poor diindenopyrazine backbone reduces the electron affinity to ?4 eV, making the compounds attractive as n-semiconductors. A simple organic field-effect transistor of 4 e –without optimization– shows electron transport with a mobility of up to 0.037 cm2 V?1 s?1.
Nitroepoxides as versatile precursors to 1,4-diamino heterocycles
Vidal-Albalat, Andreu,Rodriguez, Santiago,Gonzalez, Florenci V.
supporting information, p. 1752 - 1755 (2014/04/17)
Nitroepoxides are easily transformed into 1,4-diamino heterocycles such as quinoxalines and pyrazines by treatment with 1,2-benzenediamines and ammonia, respectively. Additionally, related saturated heterocycles, such as piperazines and tetrahydroquinoxalines, can be accessed by treatment with 1,2-diamines and a reducing agent. These transformations are efficient, provide access privileged, bioactive structures, and produce minimal waste.
Diaryldistyrylpyrazines: Solvatochromic and acidochromic fluorophores
Schmitt, Volker,Moschel, Sebastian,Detert, Heiner
, p. 5655 - 5669 (2013/09/12)
Diaryldimethylpyrazines are the starting materials for the synthesis of C2-symmetric donor- or acceptor-substituted distyrylpyrazines. The optical properties of these cruciform-shaped dyes are dominated by the distyrylpyrazine units; the photop
Chemistry of indoles carrying a basic function. Part VII. A new aspect of Stobbe reaction
Moldvai, István,Temesvári-Major, Eszter,Incze, Mária,Platthy, Tünde,Gács-Baitz, Eszter,Szántay, Csaba
, p. 309 - 319 (2007/10/03)
While performing Stobbe reactions of a succinic diester derivative (1) different routes were found leading to different indole derivatives (2-5) depending on the reaction conditions applied, thus widening the scope and limitation of this useful procedure. Simpler pyrrolidine (13) and piperidine derivatives (14, 15) were also achieved through application of the intramolecular Stobbe reaction.
Radical chain reactions of α-azido ketones with tributyltin hydride: Reduction vs nitrogen insertion and 1,2-hydrogen shift in the intermediate N-stannylaminyl radicals
Benati, Luisa,Leardini, Rino,Minozzi, Matteo,Nanni, Daniele,Spagnolo, Piero,Strazzari, Samantha,Zanardi, Giuseppe,Calestani, Gianluca
, p. 3485 - 3492 (2007/10/03)
The radical chain reactions of a variety of acyclic and cyclic α-azido ketones with tributyltin hydride have been investigated. The derived N-(tributylstannyl)aminyl radicals normally undergo H-abstraction reaction yielding corresponding amines, and thence symmetrical pyrazines by subsequent self-condensation, in competition with 1,2-H-migration from the α-carbon to nitrogen leading to α-imino ketone decomposition products with loss of the chain-carrying tributyltin radical. The noteworthy occurrence of a quite uncommon radical 1,2-hydrogen-atom shift is considered to be largely due to consequent formation of a highly stable, captodative carbon-centred radical. In contrast with our previous N-stannylaminyl radicals produced from α-azido-β-keto esters, the present aminyl congeners give poor amounts (or even none) of nitrogen-inserted amides/lactams, which are envisaged to arise from intramolecular three-membered cyclisation onto the ketone moiety followed by β-scission of the resultant alkoxyl radical. It is inferred that adequate stabilisation of the eventual ring-opened carbon radical be a major factor for the successful outcome of the regiospecific nitrogen insertion process. Evidence is also presented that chemoselective attack of tris(trimethylsilyl)silyl radical to the ketone oxygen of an α-azido ketone gives rise to deazidation as a likely consequence of β-elimination of azidyl radical by the ensuing α-silyloxyalkyl radical. X-Ray crystal structure analyses of the bromo ketone 5a, the azido ketone 5b, the caprolactam 22, and the pyrazine 26 have been performed.
Reactions of Sodium Hydrogentelluride with α-Azido Ketones and α-Azido Bromides
Suzuki, Hitomi,Kawaguchi, Takashi,Takaoka, Koji
, p. 665 - 666 (2007/10/02)
When treated with sodium hydrogentelluride in ethanol at room temperature, α-azido ketones are easily converted to pyrazines via the self-condensation of initially formed α-amino ketones followed by aerobic oxidation during work-up.On a similar treatment, activated α-azido bromide such as 1,2-diphenyl-1-azido-2-bromoethane suffers E2-type β-elimination to give the corresponding olefin as the sole product, while ordinary α-azido bromides afford complicated mixtures containing amino and olefinic compounds among other products.
2H-AZIRINES EN MILIEU ACIDE. FORMATION ET REACTIVITE D'α-IMINOCARBENIUMS
Flamming, R.,Lacombe, S.,Laurent, A.,Maquestiau, A.,Marquet, B.,Novkova, S.
, p. 315 - 328 (2007/10/02)
Reactivity of protonated azirines is studied in solution and by chemical ionization in the gazeous phase.Azirinium ion produces an α-iminocarbenium ; its reactivity is studied.Mass spectrometry (CID- MIKE technic) proves the rearrangement of the α-iminocarbenium in a nitrilium ion.This nitrilium can also be obtained in solution.
PEROXIDATION OF AZIRINES. A SEARCH FOR OXAZABICYCLOBUTANES.
Hassner, Alfred,Belinka, Benjamin A.,Steinfeld, Alvin S.
, p. 179 - 185 (2007/10/02)
Nucleophilic as well as electrophilic epoxidation of azirines leads to N-acylimines or their derivatives, possibly by way of an oxazabicyclobutane.
ACTION DE L'ACIDE FLUORHYDRIQUE SUR LES AZIRINES: SYNTHESE D'α-FLUOROCETONES ET DE DIFLUOROAMINES - ETUDE DE L'ORIENTATION DE LA REACTION
Alvernhe, Gerard,Lacombe, Sylvie,Laurent, Andre
, p. 1437 - 1440 (2007/10/02)
Addition of Olah's reagent in benzene or methylene chloride to azirines leads to the formation of difluoroamines or α-fluoroketones.This reaction has been applied to the synthesis of 17 α-fluoropregnolone.The formation of fluoroketone proceeds via a cationic intermediate.Yield is improved when using a more nucleophilic fluorinating reagent obtained by addition of triethylamine to Olah's reagent.
New Convenient Synthesis of β,β-Difluoro Amines and β,β-Difluoro-α-amino Acid Alkyl Esters by the Addition of Hydrogen Fluoride to 1-Azirines
Wade, Tamsir N.,Kheribet, Rabia
, p. 5333 - 5335 (2007/10/02)
The reaction of hydrogen fluoride in pyridine solution with a series of substituted 1-azirines (1) was investigated. β,β-Difluoro amines (4) were obtained in good yields.The exceptions are the cases of 2-phenyl-3-methyl-1-azirine (1b) and 2,3-diphenyl-1-azirine (1c) for which the direct formation of a stabilized carbocation (6) from the azirinium ion 2 is probable.The former gave 54 percent of a pyrazine (11b) and 5 percent of α-fluoropropiophenone (9b) along with 20 percent of difluoro amine 4b, while the latter afforded only the corresponding α-fluoro ketone (9c).A mechanism is suggested.
