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