Phenylsodium, deprotonation

Hydroxide and alkoxide anions are strong enough bases to promote a elimination from chloroform, and from other trihalomethanes. Carbenes can be formed from dihaloalkanes by deprotonation with stronger bases such as LDA, and even from primary alkyl chlorides using the extremely powerful bases phenylsodium or f-BuLi/f-BuOK (weaker bases just cause P elimination). 

Secondary amides may direct ortho lithiation, but they must first be deprotonated. This makes them somewhat weaker ortho directors than tertiary amides, but they may still serve the purpose quite well. For example, the lithiation and addition of benzamide (12) to aldehyde (13) was us in a synthesis of 11-deoxycaiminomycinone (Scheme 8). More recently, it has been shown that the amide monoanion may be obtained by addition of a phenylsodium to an isocyanate. ... 

Stevens rearrangements proceed smoothly whenever a benzylic group is migrating. For example, ethereal phenyllithium readily deprotonates tetramethylammon-ium bromide to give the lithium bromide-complexed ylide. This species reacts with a variety of electrophiles such as benzophenone, methyl iodide, or molecular iodine. But when the suspension is shaken in a sealed tube for 90 h at ambient temperature, the ylide decomposes entirely to trimethylamine and polymethylene (up to 74%) irrespective of the solvent used (DEE, THE, glyme). The same kind of degradation occurs when phenyllithium is replaced by -butyllithium or phenylsodium. ... 

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