Germanium reagents

Allylstannanes can be used instead of the germanium reagents, and the reaction can be performed in micellar systems." The reaction with acylsilanes provides a-hydroxy-silanes. ... 

Scheme 6.23 A polymer-supported germanium reagent for radical-mediated cyclization.

Organogermanium species are still not employed in large-scale synthetic processes, possibly because of the high price as compared to silicon and tin chemistries, and certainly because no chemistry yet discovered was unique enough to warrant the use of the more expensive germanium reagent. 

Addition of cyclic tin or germanium diamides to 45 results in displacement of the carbonyl, with the generation of new clusters 46 in high yield (Equation (8)) excess germanium reagent results in displacement of the phosphine on the platinum. Similar carbonyl displacements are observed with isocyanide ligands the products of these reactions are discussed in Section 8.07.2.7. ... 

The resistance of the E14-S bond in cyclotrimetallathianes toward nucleophilic reagents, for example, water and alcohol,62 increases on going from the silicon compounds to the corresponding germanium and tin derivatives. This is due, most likely, to the fact that the reaction of less nucleophilic ylides with phenyl groups at the phosphorus atom with trithianes (R2MS)3 (M = Ge, Sn) occurs slowly and is impeded by several side processes. 

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