The Synthesis of Metallaindene and Metallafluorene Compounds

The synthesis, spectra and properties of a series of metallaindenes (benzometalloles) and metallafluorenes (dibenzometalloles) have been investigated. Improved procedures for the formation of 1-lithio-1-phenyl-2-n-butyl-2-(2′-lithiophenyl)ethene from a reaction between n-butyllithium and diphenylacetylene have been achieved. Reactions of this dilithium intermediate with dimethyl- and diphenyldichlorosilane have afforded the respective benzosiloles in good yield. Reactions of the dilithium reagent with either dimethyltin dichloride or phenyldichlorophosphine produce the respective benzostannole and benzophosphole, whereas reactions with MCl4 (M = Si, Ge, Sn) result in formation of the corresponding metallacycles. Treatment of the benzophosphole with (n5-C5H5)Co(CO)2 or Fe3(CO)12 affords new organocobalt and -iron complexes which contain the benzophosphole ligand. The dilithium intermediate 1-lithio-1,2-diphenyl-2-(2′-lithiophenyl)ethene, prepared from phenyllithium and diphenylacetylene, reacts with titanocene dichloride to produce a benzotitanole identical with the product isolated earlier from the thermolysis of (n5-C5H5)2Ti(C6H5)2 and diphenylacetylene. Reactions between 2,2′-dilithiobiphenyl and titanocene dichloride or dimethyltin dichloride result in formation of the respective dibenzotitanole and dibenzostannole. The latter on treatment with (NH3)3Cr(CO)3 affords a tricarbonylchromium derivative.