Germylenes chalcogene reactions

A variety of preparation methods are known for transient germanium-chalcogen double bond species some of them seemed to be useful also for the synthesis of kinetically stabilized systems. Indeed, the reaction of a germylene with an appropriate chalcogen source was found to be one of the most versatile and general methods for the synthesis of stable germanium-containing heavy ketones (Scheme 21). 

Reaction of germylenes with elemental chalcogens (sulfur, selenium, tellurium) also allowed the synthesis of stable >Ge = E species. This was first exemplified by the isolation of terminal chalcogenido complexes of germanium 170152 and 171-173153 (Scheme 34). Stabilization in these cases is achieved by intramolecular complexation of the metal atom by Lewis bases. 

Although very little is known for the reactions of isolated germylenes 146, 147, and 148, diarylgermylene (150) was found to undergo a variety of reactions with olefins, dienes, acetylenes, alcohols, isothiocyanates, elemental chalcogens, and hydrosilanes as in the cases of less hindered, transient germylenes previously reported. 

---