Germanes, coupling

Ikenaga et reported that trimethyl(styryl)germanes coupled with arenediazonium tetrafluoroborates in the presence of a palladium catalyst (Scheme 36). Although the reaction proceeds smoothly under mild conditions, stereochemistry of the alkenylgennanes is not retained as was observed with alkenylsilanes shown in Scheme 2. The mechanism is ascribed to a carbopalladation route as discussed with alkenylsilanes. 

The general discussion (Section 4.02.1.4.1) on reactivity and orientation in azoles should be consulted as some of the conclusions reported therein are germane to this discussion. Pyrazole is less reactive towards electrophiles than pyrrole. As a neutral molecule it reacts as readily as benzene and, as an anion, as readily as phenol (diazo coupling, nitrosation, etc.). Pyrazole cations, formed in strong acidic media, show a pronounced deactivation (nitration, sulfonation, Friedel-Crafts reactions, etc.). For the same reasons quaternary pyrazolium salts normally do not react with electrophiles. 

Ott F. Numerical coupling of airflow, radiation and thermal behavior of the building [in German]. Thesis No. 11805, Federal Institute of Technology, Zurich, 1996. 

In 1882 Diesel met Martha Flasche, a German. The couple married in November 1883 and for the remainder of the decade lived in Paris, where they had three children Rudolph, Jr. (b. 1884), Hedy (b. 1885), and Eugen (b. 1889). 

COUPLING OF ARYL HALIDES WITH SILANES, STANNANES, GERMANES, AND BORANES 388... 

They were composed, over half of them, of Germans and Dutch.. . . Slater spoke about the stability of crystals and compounds and new quantum mechanics, not much of specific importance, but his talk of tetrahedral axes and coupling sounded so much like tetrahedrons and electron pairs that I felt much at home. Not only I, but Pauling, too, evidently, since he got up once and reminded them that the physicists were just coming to believe what the chemists had known for a long time. 112... 

In 1924 the German company Kalle Co. in Wiesbaden began production of blueprint paper, i.e. a diazo reprographic paper. In that process a sheet coated with a diazonium compound was exposed to an optical image and developed by diazo coupling using a mono-... 

Kormann, M. S. D., Carr, D., Klopp, N., et al. (2005) G-protein-coupled receptor polymorphisms are associated with asthma in a large German population. Am. J. Respir. Crit. Care. Med. 171, 1358-1362. 

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