Aryl Groups in Anions

Similarly, cleavage (37) of the chloride 3 or of the corresponding quaternary ammonium salt, 2,2,2-triphenylethyltrimethylammonium iodide (6), with sodium in liquid ammonia gave 1,1,1-triphenylethane 

Additional more-direct evidence that a normal unrearranged organoal-kali compound is formed prior to rearrangement was the observation (42) that lithium reacts with 2-chloro-l,l,l-triphenylethane at temperatures of -65° to -30°C in tetrahydrofuran (THF) to give 2,2,2-triphenyl- 

Also 2,2,2-triphenylethyllithium reacts with excess potassium tert-butox-ide in THF at -TST to give complete rearrangement of carbon skeleton in less than 10 minutes (45) this reaction is believed to occur by way of intermediate 2,2,2-triphenylethylpotassium (44). 

The above work provides compelling evidence that 2,2,2-triphenyl-ethylalkali metal compounds are rearrangement precursors. However, the circumstance that a rearrangement starts and ends with an organoalkali metal compound does not prove that the rearrangement itself directly 

One possible mechanism for phenyl migration would be by an elimination-readdition process, thus 2,2,2-triphenylethyllithium could eliminate phenyllithium, which could readd to the resulting 1,1-diphenylethene to give 1,1,2-triphenylethyllithium. 

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