Allylic anions nitrogen-substituted

A valuable feature of reactions of allylic amino organolithiums relative to their alkyl analogues is that the delocalized anion can lead to substitution at either the a- or y-position to nitrogen. Consequently, these compounds can serve as both chiral a- and y-lithioamine synthetic equivalents, as well as chiral P-homoeno-late synthetic equivalents [91 ], in substitution reactions. 

Product studies have demonstrated that I-phenyl and 1,1-diarylalkene radical cations react with nitrogen-centered nucleophiles such as amines and pyridines by both addition and deprotonation. The addition reactions occur by a mechanism analogous to that shown in Scheme I for methanol addition. Deprotonation by an amine or pyridine base is an alternate possibility for radical cations derived from 2-alkyl-substituted alke-nes and leads to an allylic radical (Eq. 19). Reduction of this radical by the sensitizer radical anion generates an anion that is protonaled at either the original position to regenerate starting... 

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