100989-94-4

Usage

Synthesis Reference(s)

Tetrahedron Letters, 26, p. 1981, 1985 DOI: 10.1016/S0040-4039(00)98357-6

Upstream product

• 2461-80-5 diphenacyl sulfide 
• 34804-73-4 4,5-diphenyl-3,6-dihydro-1,2-dithiin 
• 2548-47-2 2,3-diphenyl-1,3-butadiene 
• 70-11-1 α-bromoacetophenone 

Downstream Products

• 16939-13-2 3,4-diphenylthiophene 
• 124089-37-8 C₂₂H₁₈S 
• 124089-38-9 (Z)-1-phenylthio-2,3-diphenyl-1,3-butadiene 
• 69888-51-3 3,4-diphenyl-3-sulfolene 
• 100990-36-1 cis-3,4-dihydroxy-3,4-diphenylthiolane 1,1-dioxide 
• 83125-18-2 2,5-dibromo-3,4-diphenylthiophene 
• 872177-50-9 C₂₈H₁₈SO₄N₂ 
• 41285-62-5 2,5-bis(4-methoxyphenyl)-3,4-diphenylthiophene 
• 2548-47-2 2,3-diphenyl-1,3-butadiene 

Relevant academic research and scientific papers

Oxidation of 3,4-diaryl-2,5-dihydrothiophenes to 3,4-diarylthiophenes using CuBr2: Simple and efficient preparation of 3,4-diarylthiophenes

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.

Sulfuration of dienes with elemental sulfur

Elemental sulfur reacts with conjugated 1,3-dienes to deliver cyclic di- and polysulfides; the reaction proceeds without any activation other than heat. Treatment of cyclic polysulfide products with triphenylphosphine cleanly converts them to the corresponding disulfide in good overall yield. Additionally, some mechanistic aspects have been examined. The presence of disulfur as an active species in the sulfuration of dienes with S8 is discussed.

Modular synthesis of phenanthro[9,10-c]thiophenes by a sequence of C-H activation, suzuki cross-coupling and photocyclization reactions

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.

One-pot oxidation and bromination of 3,4-diaryl-2,5-dihydrothiophenes using Br2: Synthesis and application of 3,4-diaryl-2,5-dibromothiophenes

(Chemical Equation Presented) A class of 3,4-diaryl-2,5-dibromothiophenes (1b-5b) was synthesized by a one-pot reaction of 3,4-diaryl-2,5- dihydrothiophenes with Br2 reagent in excellent yield (83-92%). It was found that Br2 performed a double function (oxidation and bromination) during the conversion of 3,4-diaryl-2,5-dihydrothiophenes to 3,4-diaryl-2,5-dibromothiophenes. The application of 3,4-diaryl-2,5- dibromothiophenes used as building blocks was also investigated. Employing 3,4-diphenyl-2,5-dibromothiophene (1b) as a template, a class of 2,3,4,5-tetraarylthiophenes was prepared by the Suzuki coupling reaction. This provided a new and simple approach to the preparation of 2,3,4,5- tetraarylthiophenes.

EFFICIENT PREPARATION OF POLYSUBSTITUTED 1,3-DIENES FROM α,α'-DIKETO SULFIDES

A series of polysubstituted 1,3-dienes were prepared in good overall yields in three steps starting from readily accessible α,α'-diketo sulfides.

GENERAL SYNTHESIS OF 2,5-DIHYDROTHIOPHENES (3-THIOLENES) FROM DIKETO SULFIDES

The intramolecular reductive coupling reaction of easily accesible diketo sulfides by a low-valent titanium reagent (prepared from titanium(IV) chloride and zinc powder) provides an efficient general synthesis of 2,5-dihydrothiophenes.