100989-94-4Relevant articles and documents
Oxidation of 3,4-diaryl-2,5-dihydrothiophenes to 3,4-diarylthiophenes using CuBr2: Simple and efficient preparation of 3,4-diarylthiophenes
Dang, Yizhe,Chen, Yi
, p. 5661 - 5664 (2007)
A class of 3,4-diarylthiophenes was prepared in excellent yield (80-91%) by oxidation of 3,4-diaryl-2,5-dihydrothiophenes with CuBr2. The approach is also available for the synthesis of 3,4-diarylpyrroles and 3,4-diarylfuran. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Modular synthesis of phenanthro[9,10-c]thiophenes by a sequence of C-H activation, suzuki cross-coupling and photocyclization reactions
Schnapperelle, Ingo,Bach, Thorsten
, p. 9725 - 9732 (2014)
A total number of 15 different 3,4-diarylthiophenes were synthesized, which bear a chlorine atom in ortho-position of one of the aryl substituents. One aryl group was introduced by an oxidative cross-coupling reaction, involving a C-H activation at C4(3) of the thiophene core. The other aryl group was in most cases introduced by a Suzuki cross-coupling reaction, which succeeded the oxidative cross-coupling step. Photocyclization reactions of the 3,4-diarylthiophenes were performed in a solvent mixture of benzene and acetonitrile (50:50 v/v) at λ=254 nm and proceeded to the title compounds in yields of 60-82%. The selectivity of the photocyclization was determined at the ortho-chloro-substituted aryl ring by the position of the chlorine substituent. At the other ring, a single regioisomer was observed for phenyl and para-substituted phenyl groups. For 2-naphthyl and ortho-substituted phenyl rings a clear preference was observed in favor of a major regioisomer, while meta-substitution in the phenyl ring led to a about 1:1 mixture of 5- and 7-substituted phenanthro[9,10-c]thiophenes. Mechanistically, the photocyclization is likely to occur as a photochemically allowed, conrotatory [(4n+2)π] process accompanied by elimination of HCl. It was shown for two phenanthro[9,10-c]thiophene products that they can be readily brominated in positions C1 and C3 (74-77%), which in turn allows for further functionalization at these positions, for example, in the course of halogen-metal exchange and polymerization reactions. Three C-C bond formation reactions are successively coupled in a convergent synthesis of phenanthro[9,10-c]thiophenes A. The key reaction is an unprecedented photocyclization of precursors B, which proceeds cleanly at λ=254 nm (60-82% yield). Diarylthiophenes B are conveniently assembled employing a sequence of oxidative and regular Suzuki cross-coupling reactions.
EFFICIENT PREPARATION OF POLYSUBSTITUTED 1,3-DIENES FROM α,α'-DIKETO SULFIDES
Nakayama, Juzo,Machida, Haruki,Saito, Ryuji,Akimoto, Keiichi,Hoshino, Masamatsu
, p. 1173 - 1176 (2007/10/02)
A series of polysubstituted 1,3-dienes were prepared in good overall yields in three steps starting from readily accessible α,α'-diketo sulfides.
