1337877-57-2Relevant academic research and scientific papers
Concise synthesis of well-defined linear and branched oligothiophenes with nickel-catalyzed regiocontrolled cross-coupling of 3-substituted thiophenes by catalytically generated magnesium amide
Tanaka, Shota,Tanaka, Daiki,Tatsuta, Go,Murakami, Kohei,Tamba, Shunsuke,Sugie, Atsushi,Mori, Atsunori
supporting information, p. 1658 - 1665 (2013/02/25)
The synthesis of linear and branched oligothiophenes of well-defined structures is performed with regioselective deprotonation of 3-substituted thiophenes and nickel-catalyzed cross-coupling of the thus formed metalated species with a bromothiophene. The reaction of 3-hexylthiophene with EtMgCl and 2,2,6,6-tetramethylpiperidine (TMP-H, 10 mol %) induces the metalation selectively at the 5-position by use of the catalytically generated hindered magnesium amide (TMPMgCl) and the subsequent reaction of a 2-halo-3- hexylthiophene (bromide or chloride) in the presence of a nickel catalyst affords a head-to-tail (HT)-type dimer. By repeating the same sequence, the linear oligothiophene up to a 4-mer is synthesized in good yield. The reaction of 3-hexylthiophene with 2,3-dibromothiophene also takes place to afford a branched oligothiophene 3-mer in quantitative yield. The obtained 3-mer is also metalated at the sterically less-hindered position in a regioselective manner furnishing a 7-mer in >99 % yield after a further coupling reaction with 2,3-dibromothiophene. These dendrimers react with several multifunctionalized organic electrophiles, leading to a variety of branched oligothiophenes. Copyright
C-H arylation of 3-substituted thiophene with regioselective deprotonation by tmpMgCl·LiCl and transition metal catalyzed cross coupling
Tanaka, Shota,Tamba, Shunsuke,Sugie, Atsushi,Mori, Atsunori
, p. 255 - 266 (2013/08/23)
The reaction of 3-hexylthiophene with Knochel-Hauser base (TMPMgCl·LiCl) induced the metalation at the 5-position of the thiophene ring selectively. Following addition of several aryl halides in the presence of a nickel or palladium catalyst afforded regi
Synthesis of well-defined head-to-tail-type oligothiophenes by regioselective deprotonation of 3-substituted thiophenes and nickel-catalyzed cross-coupling reaction
Tanaka, Shota,Tamba, Shunsuke,Tanaka, Daiki,Sugie, Atsushi,Mori, Atsunori
supporting information; experimental part, p. 16734 - 16737 (2011/12/14)
Iterative growth of thiophene oligomers by single-step extensions has been realized by regioselective metalation of 3-substituted thiophenes with the Knochel-Hauser base (TMPMgCl·LiCl) and coupling with bromothiophene using a nickel catalyst. Treatment of 3-hexylthiophene with TMPMgCl·LiCl induces metalation at the 5-position selectively. Subsequent addition of 2-bromo-3-hexylthiophene and a nickel catalyst leads to the corresponding bithiophene. The obtained bithiophene is converted to the terthiophene and then to the quaterthiophene by repeating the similar protocol. A concise synthesis of MK-1 and MK-2, which are organic dye molecules bearing an oligothiophene moiety that are used in photovoltaic cells, has been achieved.
