54600-85-0Relevant articles and documents
Diindenopyrazines: Electron-Deficient Arenes
Brosius, Victor,Bunz, Uwe H. F.,Freudenberg, Jan,Hippchen, Nikolai,Rominger, Frank,Weigold, Svenja
, 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.
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
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.
