Tungsten oxo adamantylidenes (=Ad) are a new class of readily accessible alkylidenes, that opens the possibility to evaluate broader molecular and supported olefin metathesis catalysts. In this context, W(O)(=Ad)X2, with X=pyrrolide perfluoro-tert-butoxide, were grafted on partially dehydroxylated silica, generate corresponding silica-supported tungsten adamantylidenes. The high thermal stabili...