Triphenylmethide, lithium

Die Reaktion von aliphatischen N-Sulfinyl-aminen mit Allyl-halogeniden in Gegenwart von nukleophilen Basen wie Lithium-triphenylmethid Oder Kalium-tert.-butoxid fuhrt zur Bildung von 4-Amino-l-alkenen1. 

The triphenylmethyl carbanion, the trityl anion, can be generated by the reaction of triphenylmethane with the very powerful base, n-butyllithium. The reaction generates the blood-red lithium triphenylmethide and butane. The triphenylmethyl anion reacts much as a Grignard reagent does. In the present experiment it reacts with carbon dioxide to give triphenylacetic acid after acidification. Avoid an excess of n-butyllithium on reaction with carbon dioxide, it gives the vile-smelling pentanoic acid. 

The difference in site of attack depending on the size of the nucleophiles is illustrated by the observations that methyl lithium, lithium dimethylamide or the lithium salt of dimethyl sulphoxide all bring about nucleophilic addition of the anion at the 4-position (mainly) whereas lithium dicyclohexylamide or sodium triphenylmethide react exclusively at the 6-position [141]. 

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