The modulation of 9-Chloro-9-Phosphaalkenylchloro-9-Germafluorene reactivity through organolithium reagents

The reactivity of 9-chloro-9-phosphaalkenylchloro-9-germafluorene towards organolithium reagents is influenced by their nature. Reagents such as methyllithium and n-butyllithium afford alkylated species of phosphaalkenylchloro-germafluorene at the Ge-Cl unit while the reactions of bulkier sec-butyllithium and tert-butyllithium undergo with the formation of symmetrical and unsymmetrical dimers through involvement of the PC and/or Ge-C moieties. [Display omitted] The reactivity of 9-chloro-9-phosphaalkenylchloro-9-germafluorene stabilized by the introduction of the germanium atom into a fluorenyl system, was tested in reaction with lithium derivatives as methyllithium, normal-, sec- and tert-butyllithium. The reactions underwent, depending on the used organolithium derivative, either with the alkylation of the germanium atom or through a lithiation of the carbon atom of the phosphaalkenyl unit, and the successive formation of a carbanion through elimination of LiCl followed by the dimerization of this intermediate species.