DUGi

Synthesis and characterization of a homogeneous and silica supported homoleptic cationic tungsten(VI) methyl complex: Application in olefin metathesis

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@2072@@298560

A method for the synthesis of a homogeneous cationic tungsten(VI)pentamethyl complex [(WMe5)+(C6F5)3BMe−] from neutral tungstenhexamethyl (WMe6) and a silica supported cationic tungstentetramethyl complex [([triple bond, length as m-dash]Si–O–)WMe4+ (C6F5)3BMe−] from a neutral silica supported tungstenpentamethyl complex [([triple bond, length as m-dash]Si–O–)WMe5] is described. In both cases a direct demethylation using the B(C6F5)3 reagent was used. The aforesaid complexes were characterized by liquid or solid state NMR spectroscopy. Interestingly, the homogeneous cationic complex [(WMe5)+(C6F5)3BMe−] shows moderate activity whereas the supported cationic complex [([triple bond, length as m-dash]Si–O–)WMe4+(C6F5)3BMe−] exhibits good activity in olefin metathesis reactions

This work was supported by funds from the King Abdullah University of Science and Technology (KAUST) office of sponsored research (OSR). A. P. thanks the Spanish MINECO for the project CTQ2014-59832-JIN. The authors also thank Dr Nassima Riache for fruitful discussions

Reaction mechanisms (Chemistry)