Oxidation And Bromination Of 3, 4-Diaryl-2, 5-dihyrothiophenes

3,4-Diarylthiophenes are one of important organic materials for medicinal chemistry and material chemistry. In the thesis, 3,4-diaryl-2,5-dihydrothiophenes were employed as starting materials and reacted with reagents CuBr2 and Br2, respectively, both 3,4-Diarylthiophenes and 3,4-Diaryl-2,5-dibromothiophenes in excellent yields were obtained. Besides, the reaction condition and mechanism were primarily explored.1. A class of 3,4-diaryl-2,5-dihydrothiophenes was synthesized and employed as starting materials to react with reagent CuBr2 , It is found that 3,4-diaryl-2,5-dihydrothiophenes were dehydrogenated to convert into 3,4-diarylthiophenes in excellent yields by oxidation with CuBr2 reagent. This may provide a new approach to the preparation of 3,4-diarylthiophenes.2. A class of 3,4-diaryl-2,5-dibromothiophenes was synthesized in one-pot reaction by treatment of 3,4-diaryl-2,5-dihydrothiophenes with Br2 reagent. The reaction has many advantages: simplicity, quickness, and availability. Br2 reagent acted as both oxidizer and bromine reagent in the reaction.3. 3,4-diphenyl-2,5-dibromothiophene used as a new building block was investigated. A class of 2,3,4,5-tetraarylthiophenes were synthesized by treatment of 3,4-diphenyl-2,5-dibromothiophene with different aromatic boronic acids reagents via Suzuki coupling reaction. This may provide a facile synthetic route for the preparation of 2,3,4,5-tetraarylthiophenes.