Role of Copper Species in the Oxidative Dimerization of Arylboronic Acids: Synthesis of Symmetrical Biaryls
摘要:
Certain Cu(I) and Cu(II) salts are able to mediate the dimerization of arylboronic acids in DMF. They provide the corresponding symmetrical biaryls in moderate to very good yields. It is possible to run the reaction catalytically under an oxygen atmosphere without a significant loss of yields.
Five newly designed organic small molecules (DSBTs, 1–5) with 3,3′-bithienyl unit had been successfully synthesized with 3-bromothiophene as the starting material. In both UV–vis absorption and fluorescence emission investigation, compound 3 with nitro-substitution exhibited the largest bathochromic shift and narrowest optical bandgap among 1–5. Further photophysical studies showed that 3 had obvious
Oxidative intramolecular cyclization of 2,2′-bis(1,4-dithiafulven-6-yl)-3,3′-bithienyls affording novel bis(1,3-dithiole) electron donors
作者:Akira Ohta、Yoshiro Yamashita
DOI:10.1039/c39950001761
日期:——
The title bis(1,3-dithiole) compounds containing a 3,3â²-bithienyl unit undergo an intramolecular coupling reaction at the 6-positions of the dithiafulvenyl groups by oxidation to give cyclization products in high yields.
Comparison of Ullmann/RCM and Ullmann/Bis-hydrazone Coupling Reactions; New Access to Benzodithiophenes for Dye-Sensitized Solar Cell and Thiahelicene Applications
The use of CuTC (Liebeskind's catalyst), followed by methylenation and ring-closing metathesis, or bis-hydrazone coupling reactions is described. This approach establishes an alternative non-photochemical synthesis of the strategically important 1,2-b:4,3-b' BDT regioisomer, which has previously been underused in applications such as dye-sensitized solar cells and nonlinear optics because of the difficulty of synthesis on a large scale.
Meunier,P., Journal of Heterocyclic Chemistry, 1978, vol. 15, p. 593 - 599