Modular and Selective Arylation of Aryl Germanes (C-GeEt3) over C-Bpin, C-SiR3 and Halogens Enabled by Light-Activated Gold Catalysis was written by Sherborne, Grant J.;Gevondian, Avetik G.;Funes-Ardoiz, Ignacio;Dahiya, Amit;Fricke, Christoph;Schoenebeck, Franziska. And the article was included in Angewandte Chemie, International Edition in 2020.Recommanded Product: 162258-89-1 This article mentions the following:
Selective Csp2-Csp2 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 Au catalysis, which facilitates the selective coupling of C-Ge with aryl diazonium salts. Contrary to previous light-/Au-catalyzed couplings of Ar-N2+, which were specialized in Ar-N2+ scope, the authors present conditions to efficiently couple electron-rich, electron-poor, heterocyclic and sterically hindered aryl diazonium salts. The authors’ computational data suggest that while electron-poor Ar-N2+ salts are readily activated by Au 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. In the experiment, the researchers used many compounds, for example, 4-Bromo-4′-tert-butylbiphenyl (cas: 162258-89-1Recommanded Product: 162258-89-1).
4-Bromo-4′-tert-butylbiphenyl (cas: 162258-89-1) belongs to organobromine compounds. Bromine is more electronegative than carbon (2.9 vs 2.5). Consequently, the carbon in a carbon–bromine bond is electrophilic, i.e. alkyl bromides are alkylating agents. Many of the alkyl bromine derivatives are excellent alkylating agents since bromides are good leaving groups. Tribromides, like tetrabutylammonium tribromide, are used as a solid source of bromine. N-bromosuccimide (NBS) is used for the selective bromination of allylic bonds.Recommanded Product: 162258-89-1
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary