61124-36-5Relevant academic research and scientific papers
Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations
Deckers, Kristina,Fricke, Christoph,Schoenebeck, Franziska
supporting information, p. 18717 - 18722 (2020/08/25)
While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism.
Gold-Catalyzed Chemoselective Couplings of Polyfluoroarenes with Aryl Germanes and Downstream Diversification
Dahiya, Amit,Fricke, Christoph,Schoenebeck, Franziska
supporting information, p. 7754 - 7759 (2020/04/30)
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.
Orthogonal Nanoparticle Catalysis with Organogermanes
Fricke, Christoph,Sherborne, Grant J.,Funes-Ardoiz, Ignacio,Senol, Erdem,Guven, Sinem,Schoenebeck, Franziska
supporting information, p. 17788 - 17795 (2019/11/13)
Although nanoparticles are widely used as catalysts, little is known about their potential ability to trigger privileged transformations as compared to homogeneous molecular or bulk heterogeneous catalysts. We herein demonstrate (and rationalize) that nanoparticles display orthogonal reactivity to molecular catalysts in the cross-coupling of aryl halides with aryl germanes. While the aryl germanes are unreactive in LnPd0/LnPdII catalysis and allow selective functionalization of established coupling partners in their presence, they display superior reactivity under Pd nanoparticle conditions, outcompeting established coupling partners (such as ArBPin and ArBMIDA) and allowing air-tolerant, base-free, and orthogonal access to valuable and challenging biaryl motifs. As opposed to the notoriously unstable polyfluoroaryl- and 2-pyridylboronic acids, the corresponding germanes are highly stable and readily coupled. Our mechanistic and computational studies provide unambiguous support of nanoparticle catalysis and suggest that owing to the electron richness of aryl germanes, they preferentially react by electrophilic aromatic substitution, and in turn are preferentially activated by the more electrophilic nanoparticles.
Photochemical Addition of Benzyltriethylgermane and Dibenzyldiethylgermane to Olefines
Kobayashi, Masanori,Yoshida, Masato,Kobayashi, Michio
, p. 3169 - 3174 (2007/10/02)
A novel photochemical addition of a germanyl radical to the olefinic double bond was discovered when benzyltriethylgermane or dibenzyldiethylgermane was irradiated with a medium-pressure mercury lamp in the presence of olefins.
