68972-13-4Relevant academic research and scientific papers
Gold-Catalyzed Chemoselective Couplings of Polyfluoroarenes with Aryl Germanes and Downstream Diversification
Dahiya, Amit,Fricke, Christoph,Schoenebeck, Franziska
, p. 7754 - 7759 (2020)
This report describes the chemoselective coupling of polyfluoroarenes with aryl germanes in the presence of aromatic C-I, C-Br, C-Cl, C-OTf, and C-SiMe3 groups, as well as demonstrates the further downstream diversification to give richly functionalized and highly fluorinated polyarenes. The strategy relies on an in situ Umpolung of the FnArH, followed by selective Au(I)/Au(III)-catalyzed coupling with electron-poor or-rich aryl germanes, even in the presence of challenging ortho-substituents, and widens the currently available coupling space in oxidative gold catalysis to previously inaccessible electron-poor/electron-poor biaryls.
Modular and Selective Arylation of Aryl Germanes (C?GeEt3) over C?Bpin, C?SiR3 and Halogens Enabled by Light-Activated Gold Catalysis
Dahiya, Amit,Fricke, Christoph,Funes-Ardoiz, Ignacio,Gevondian, Avetik G.,Schoenebeck, Franziska,Sherborne, Grant J.
supporting information, p. 15543 - 15548 (2020/06/22)
Selective C (Formula presented.) –C (Formula presented.) couplings are powerful strategies for the rapid and programmable construction of bi- or multiaryls. To this end, the next frontier of synthetic modularity will likely arise from harnessing the coupling space that is orthogonal to the powerful Pd-catalyzed coupling regime. This report details the realization of this concept and presents the fully selective arylation of aryl germanes (which are inert under Pd0/PdII catalysis) in the presence of the valuable functionalities C?BPin, C?SiMe3, C?I, C?Br, C?Cl, which in turn offer versatile opportunities for diversification. The protocol makes use of visible light activation combined with gold catalysis, which facilitates the selective coupling of C?Ge with aryl diazonium salts. Contrary to previous light-/gold-catalyzed couplings of Ar–N2+, which were specialized in Ar–N2+ scope, we present conditions to efficiently couple electron-rich, electron-poor, heterocyclic and sterically hindered aryl diazonium salts. Our computational data suggest that while electron-poor Ar–N2+ salts are readily activated by gold under blue-light irradiation, there is a competing dissociative deactivation pathway for excited electron-rich Ar–N2+, which requires an alternative photo-redox approach to enable productive couplings.
