Germyls unsaturated

Germyl hydrides readily undergo oxidative addition to the low-valent coordinatively unsaturated transition-metal complexes. Optically active [Co(CO)4GeMe(l-Np)Ph] was... 

The nature of the unsaturated compounds dictate the reaction pathway to a great extent, but it still remains unclear why a radical mechanism predominates in some cases and why a radical hydrogermylation may lead to a radical double germylation. 

Cyclization of unsaturated germanes under ionic conditions upon treatment with chloroplatinic acid, as well under homolytic conditions by treatment by AIBN at 100°C or upon uv irradiation has been described by Satge. Intramolecular addition of germyl radical is a very efUcient process since the compound 142, on AIBN initiation at 100°C, gives the cyclized product 143 in 70% yield (Scheme 65). This is the only example reported of intramolecular addition in the Cyll/Cyl2 case. Even in the Cy3/Cy4 case, radical cyclization toward the (Cy4) compound is observed, although only in 12% yield. 

Poly(germaniiim enolate) (186) has been synthesized as shown in Scheme 46.2 0,261 jjj order to form a polymeric material, a,P-unsaturated carbonyl compound was required to react with a germylene in the presence of a lithium catalyst such as LiCl or LiR. It was believed that initial formation of a germyl anion species was achieved by coordination of the Li catalyst to the germylene compound. 

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