Organolithium compounds, electron-transfer formation

ORGANOLITHIUM COMPOUNDS AS ELECTRON-TRANSFER AGENTS IN CARRON-CARRON ROND FORMATION. An instructive example of how RLi, rather than lithium metal, can act as an electron source (cf. Figure 2) is the cyclization of 2-(2-biphenylyl)-l,l-diphenylethene (34) by n-butyllithium. To enhance electron transfer, the chelating strong-donor TMEDA was employed. The observed cyclization to 9-(diphenylmethyl)fluorene (35) can best be explained by electron transfer (Scheme XIII).2... 

Reactions (1) and (2) involve single electron transfers from the metal to either the ketone or the halide. In the latter case this leads to the formation of what the authors named the precursors of the organolithium compound or transitory species on the metal surface. 

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