Application of imidazolinium salts and N-heterocyclic olefins for the synthesis of anionic and neutral tungsten imido alkylidene complexes

Abstract

The synthesis, single crystal X-ray structure and activity in olefin metathesis of novel anionic tungsten imido alkylidene complexes [1,3-bis-(2,4,6-trimethylphenyl)imidazolinium]⁺ [W(N-2,6-iPr₂C₆H₃)(CHCMe₂Ph)(2,5-Me₂Pyr)₂Cl]⁻, [1,3-bis-(2,4,6-trimethylphenyl)imidazolinium]⁺ [W(N-2,6-iPr₂C₆H₃)(CHCMe₂Ph)(2,5Me₂Pyr)₂(OC₆F₅)]⁻, and [1,3-bis-(2,6-diisopropylphenyl)imidazolinium]⁺ [W(N-2,6-iPr₂C₆H₃)(CHCMe₂Ph)(2,5-Me₂Pyr)Cl₂]⁻ are reported. Additionally, the first example of a bis(N-heterocyclic olefinium) alkylidene tungstate, W(N-2,6-iPr₂C₆H₃)(CHCMe₂Ph)(2-methylene-1,3,4,5-tetramethyl-imidazoline)₂(OTf)₂, is described, including preparation, crystal structure and catalytic activity.