Treating the bis(imido) W(NAr)(2)Cl-2(DME) with 2 equiv of cyclooctyne in pentane results in precipitation of a yellow complex containing a 6-membered metallacycle, W(=C8H12=C8H12=NAr)(NAr)Cl-2 (1). This easily accessible compound was tested for its ability to effect carbonyl olefination/ring-closing metathesis (CO/RCM) with two substrates. One ketone was tested, 1-acetyl-1-(3-butenyl)cyclopentane, which generates 1-methylspiro[4.4]non-1-ene on COMM An ester, 4-benzoyloxybut-1-ene, was also test with 1 for COMM The dichloride 1 was found to be inactive; consequently, several derivatives were prepared, fully characterized including X-ray diffraction, and tested: W(=C8H12=C8H12=NAr)(NAr)(OEt)(2) (2), W(=C8H12=C8H12=NAr)(NAr)(OC6H4-P-OMe)(2) (3), W(=C8H12=C8H12=NAr)(NAr)(OC6F5)(2) (4), and W(=C8H12=C8H12=NAr) (NAr)(Cl)(OTf) (5). In addition, synthesis of cationic complexes was attempted using 1 with Na[B(Ar-F)(4)] or AlCl3. We were unsuccessful in fully characterizing the cations; however, these cations generated in situ show very high activity for CO/RCM with these substrates.