108030-80-4Relevant articles and documents
Direct C-H photoarylation of diazines using aryldiazonium salts and visible-light
Silva, Rodrigo C.,Villela, Lucas F.,Brocksom, Timothy J.,De Oliveira, Kleber T.
, p. 31115 - 31122 (2020/09/23)
In this study, direct C-H photoarylation of pyrazine with aryldiazonium salts under visible-light irradiation (blue-LEDs) is described, and additional examples including photoarylations of pyrimidine and pyridazine are also covered. The corresponding aryl-diazines were prepared in yields up to 84% only by mixing and irradiating the reaction with no need for an additional photocatalyst. We demonstrate the efficacy of this protocol by the scope with electron-donor, -neutral, and -withdrawing groups attached at the ortho, meta, and para positions of the aryldiazonium salts; the results are better than those reported for ruthenium-complex mediated photoarylations. Additionally, we demonstrate the robustness of this methodology with a 5 mmol scaled-up experiment. Mechanistic studies were carried out giving support to the proposal of a photocatalyzed approach by an electron donor-acceptor (EDA) complex, also highlighting the crucial role that solvents play in the formation of the EDA complex. This journal is
Electrochemical oxidation synergizing with Br?nsted-acid catalysis leads to [4 + 2] annulation for the synthesis of pyrazines
Liu, Kun,Song, Chunlan,Wu, Jiarong,Deng, Yuqi,Tang, Shan,Lei, Aiwen
, p. 765 - 769 (2019/02/27)
An electrochemical dehydrogenative [4 + 2] annulation for the synthesis of pyrazines has been developed under undivided electrolytic conditions. In this protocol, neither external chemical oxidants nor transition-metal catalysts are needed, and a wide range of substituted pyrazines could be obtained from simple ketones and diamines in high efficiencies. Of note is that this electrolysis could also be extended for the construction of biheteroarenes and large π systems with good yields.
Copper-catalyzed cross-coupling of aryl-, primary alkyl-, and secondary alkylboranes with heteroaryl bromides
Bergmann, Allison M.,Oldham, Adam M.,You, Wei,Brown, M. Kevin
supporting information, p. 5381 - 5384 (2018/06/01)
A method for the Cu-catalyzed cross-coupling of both aryl and alkylboranes with aryl bromides is described. The method employs an inexpensive Cu-catalyst and functions for a variety of heterocyclic as well as electron deficient aryl bromides. In addition, aryl iodides of varying substitution patterns and electronic properties work well.
