Other Anionic Rearrangements, Known and Unknown

Among the other unknown homoatomic 1,2-anionic rearrangements, several will be detectable only with great difficulty. For example, in silyl hydroperoxide anions, RjSi—O—0 , silicon may migrate from one 

Difficulties of another sort attend the study of anionic rearrangements between metalloid atoms (Si—Si, P—P, Ge—Ge, etc.). Here the chemistry is complicated by the easy cleavage of the metal-metal bonds under highly basic conditions. However, it is possible that such anionic rearrangements can be observed with careful choice of systems. 

This leaves only the challenging ease of the ethylene rearrangement, C=C. No examples are known, although anionic migration in this sense, accompanied by loss of halide, is proposed as a mechanism for the Fritsch-Buttenberg-Weichell rearrangement (12a, 13a). 

A possible 1,2-anionic rearrangement on a benzene ring has been 

Study of anions of differentially substituted silyl olefins seems very much worthwhile. 

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