Addition and cycloaddition reactions of [Cp(CO)2Re.tplbond.CTol]+ with cis-azoarenes, epoxides, 3,3-dimethyloxetane, 2-methylaziridine, propylene sulfide, and benzophenone hydrazone. Displacement of the cyclopentadienyl ligand from the resultant metallacycles by trimethylphosphine

Abstract

The BPh[sub 4][sup [minus]] salt of the carbyne complex [Cp(CO)[sub 2]Re[equivalent to]CTol][sup +], 1, undergoes net [2 + 2] cycloaddition of cis-azobenzene, cis-axotoluene, and benzo [c] cinnoline to give new complexes 5a, 5b, and 7, respectively, which possess four-membered metallacycles. The BCl[sub 4][sup [minus]] salt of complex 1 initially reacts with cis-azobenzene and cis-azotaluene to give metallacycles 5a and 5b, but upon stirring these complexes abstract chloride from the BCl[sub 4][sup [minus]] anion and insert a CO ligand into the Re-carbon bond of the metallacycle to give new complexes possessing five-membered metallacycles. With benzo [c] cinnoline, the BCl[sub 4][sup [minus]] salt of complex 1 reacts to give initially the metallacycle 7 formed from the BPh[sub 4][sup [minus]] salt, but upon stirring, the benzo [c] cinnoline group is displaced by chloride (from BCl[sub 4][sup [minus]]) to yield the chlorocarbene complex Cp(CO)[sub 2]Re[equivalent to]C-(Cl)Tol. 26 refs., 8 figs., 9 tabs.