7311-68-4Relevant articles and documents
Insights into the mechanism of the site-selective sequential palladium-catalyzed cross-coupling reactions of dibromothiophenes/ dibromothiazoles and arylboronic acids. Synthesis of PPARβ/δ agonists
Pereira, Raquel,Furst, Audrey,Iglesias, Beatriz,Germain, Pierre,Gronemeyer, Hinrich,De Lera, Angel R.
, p. 4514 - 4525 (2008/09/19)
A reactivity study, aided by NMR spectroscopy, allowed a mechanistic rationale to be postulated for the palladium-catalyzed regioselective coupling of arylboronic acid (and arylstannane where feasible) at the position next to the sulfur atom in functional
Synthesis and antitumour activity of new derivatives of flavone-8- acetic acid (FAA). Part 31): 2-Heteroaryl derivatives
Aitken, R. Alan,Bibby, Michael C.,Bielefeldt, Florian,Double, John A.,Laws, Andrea L.,Mathieu, Anne-Laure,Ritchie, Robert B.,Wilson, David W. J.
, p. 405 - 411 (2007/10/03)
A range of 14 derivatives of flavone-8-acetic acid (FAA) with a heterocyclic substituent in place of the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. Some of the compounds, notably 2c,d and s, showed significant in vivo activity and these require further studies in order to evaluate their potential for development.
Synthesis of Thieno--, -- and --thiophenes and Thieno--, -- and --thienopyrimidin-7(6H)-ones Starting from Thiophene
Hawkins, David W.,Iddon, Brian,Longthorne, Darren S.,Rosyk, Peter J.
, p. 2735 - 2744 (2007/10/02)
3-Bromo-, 3,5-dibromo- and 3,4,5-tribromo-2-thienyllithium have been prepared by bromine ->lithium exchange and converted into a number of thiophene derivatives, including the corresponding 2-carbaldehydes.The aldehydes have been converted into the corresponding thiophene-2-carbonitriles.Metallation of 2,5-dibromo- or 2,4,5-tribromo-thiophene with LDA occured at a vacant 3-position but the resulting 3-lithiated thiophenes rearranged (mechanism discussed) to 3,5-dibromo- and 3,4,5-tribromo-2-thienyllithium, which were quenched with various electrophiles.Attempts to dilithiate 2,5-dibromothiophene with LDA were unsuccessful. 3,4-Dibromo-2,5-dilithiothiophene was prepared from 2,3,4,5-tetrabromothiophene but it failed to yield the 2,5-dicarbaldehyde with N,N-dimethylformamide.The title thienothiophenes were prepared by reaction of a 3-bromothiophene-2-carbaldehyde, a 2-bromothiophene-3-carbaldehyde (prepared by bromination of a thiophene-3-carbaldehyde) or a 4-bromothiophene-3-carbaldehyde, or a corresponding nitrile, with ethyl 2-sulfanylacetate or 2-sulfanylacetamide.Thienothiophenes carrying an o-aminocarboxamide substitution pattern gave the title thienothienopyrimidinones with triethyl orthoformate.
Thiophene S,N-Ylides: A New Versatile Class of Sulphimides
Meth-Cohn, Otto,Vuuren, Gerda van
, p. 233 - 244 (2007/10/02)
Tetrachlorothiophene reacts with methyl, ethyl, and phenyl azidoformates and with toluene-p-sulphonyl azide at 130-150 deg C to give stable thiophene S,N-ylides. 2,5-Dichloro and 2,5-dibromo-thiophene and tetrabromothiophene yield products derived by nitrene attack at the α-position.The S,N-ylides undergo ready photolysis to liberate the parent nitrene, and react with a wide variety of electron-rich dienophiles as 4?-components to give tetrachlorodihydrobenzenes with extrusion of a thionitroso compound.With dienes the ylides react either as 2?- or 4?-systems.Thus with anthracene a dihydrothiophene analogue of triptycene is generated efficiently aromatised and de-ylidated with zinc in methanol.With dimethyl acetylenedicarboxylate the ylides yield a thiazocine by a novel ring expansion.Oxidation of the ylide system with 3-chloroperbenzoic acid gives the corresponding ylide S-oxide.Tetrachlorothiophene also reacts efficiently with diazoalkanes under rhodium acetate catalysis to give thiophene S,C-ylides, which undergo cycloaddition with nucleophilic alkenes much more slowly than their nitrogen analogues.
