129708-81-2Relevant academic research and scientific papers
Syntheses of sterically hindered zwitterionic pyridinium phenolates as model compounds in nonlinear optics
Diemer, Vincent,Chaumeil, Helene,Defoin, Albert,Fort, Alain,Boeglin, Alex,Carre, Christiane
experimental part, p. 1767 - 1776 (2009/04/11)
Pyridinium phenolates possess a dissymmetric delocalised π-electron system providing a huge quadratic nonlinearity. They are a promising class of molecules for applications in photoelectronics and photonics. Semiempirical calculations indicate that the interplanar angle between the two aromatic rings leads to enhancement in the NLO properties of these compounds. The confirmation of this feature may be provided by the study of a new series of sterically hindered pyridinium phenolates 2a-e bearing two tert-butyl substituents at the ortho position(s) of the phenolate functionality. Such bulky groups would enhance the solubility of zwitterions in organic solvents and would limit the formation of aggregates. Their efficient preparations by using Suzuki cross-coupling reactions involving 3,5-dialkylated 4-bromopyridine N-oxides are described herein. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Electrosynthesis of Unsymmetrical Polyaryls by a SRN1-Type Reaction
Boy, P.,Combellas, C.,Suba, C.,Thiebault, A.
, p. 4482 - 4489 (2007/10/02)
Unsymmetrical polyaryls are electrosynthesized in liquid ammonia by a single-step SRN1 reaction in the presence of a redox mediator starting from aromatic halides and 2,6-di-tert-butyl phenoxide.With monoaryl halides activated by electron-withdrawing substituents (N of pyridyl or quinolyl, trifluoromethyl, cyano, sulfone, ester, ketone, alkyl sulfide, N(1+) of anilinium), biaryls are obtained in good yields (between 50 and 95percent).The yields of ter- and quateraryls are lower (40percent maximum).The reaction is extended to other ortho-disubstituted phenols.Elimination reactions of the tert-butyl groups from the products are achieved by a Friedel-Crafts reaction using either trifluoromethanesulfonic acid or aluminum trichloride as catalysts.
Theory and Experimental Illustration of Preparative Electrochemistry Using Redox Catalysis of Electron Transfer Initiated Radical Chain Reactions. Application to the Cross-Coupling between Aryl Halides and Phenoxide Ions
Alam, N.,Amatore, C.,Combellas, C.,Thiebault, A.,Verpeaux, J. N.
, p. 6347 - 6356 (2007/10/02)
A general equation predicting the yield of electron transfer initiated radical chain reaction (SRN1 and related mechanisms) under preparative electrochemical conditions is given for situations where the electron-transfer activation of the chain is performed by means of a redox mediator.Simple tests, allowing for the choice of proper redox mediator, are given, and their origins established and discussed.The validity and application of this simple model is shown and discussed for the case of the SRN1-like reaction involving di-tert-butylphenoxide as a nucleophile, to afford biaryls of interest for their properties in nonlinear optics.
