Aryl in Radical Anions of Aromatic Hydrocarbons and Related Reactions

MIGRATIONS OF ARYL IN RADICAL ANIONS OF AROMATIC HYDROCARBONS AND RELATED REACTIONS 

The reductive rearrangement of 1,1,3-triphenylindene by sodium was discovered, but misinterpreted, by Schlenk and Bergmann (75). According to Ziegler and Grossman (97), the reaction proceeds as follows  

In a reinvestigation of the reaction of Schlenk and Bergmann, Miller and Boyer 64) found that reaction of 1,1,3-triphenylindene with sodium or sodium-potassium alloy in THF gave, after addition of water, 1,2,3-triphenylindane (rather than the indene). These workers suggest that the reaction likely proceeds via the radical anion 95 which by [1,2] migration of phenyl gives a more stable o-quinodimethane anion radical % which upon reduction leads to the dianion 97. Evidently in THF hydride loss from 97 is slower than in diethyl ether, where 99 is formed prior to 

That alkyl groups may migrate in radical anions under favorable circumstances is borne out by the rearrangement 14) of naphthobicyclo-butane radical anion 105 to the radical anion of pleiadiene 106. This 

We have indeed in the course of some of our reactions (27) of aryl- 

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