The GTP Process

The tetrabutylammonium (TBA) catalysts are slowly consumed during the progress of the polymerization and in longer runs additional amounts 

It would be of interest to see if the more stable cesium carboxylates would be better catalysts for GTP than TBA carboxylates since Quirk showed that cesium 9-methylfluorenide works as well as TBA 9-methylfluorenide as a catalyst in his mechanism studies [6]. 

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Where the catalyst is less nucleophilic, e.g. potassium fluoride or solid caesium fluoride, only one fluoride ion is likely to coordinate at all firmly to the silane. The nucleophilic reactant will then also be able to coordinate to the electrophilic silicon atom, itself receiving further activation in the process, and reaction ensues by intramolecular transfer about the hexacoordinate silicon atom as demonstrated in the GTP process. Less nucleophilic substrates such as alkyl halides are unreactive in these circumstances. 

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