Synthesis of Polyisocyanide Compounds via α-Metalation Reactions

α-Metalated isocyanides were first prepared over 20 years ago¹and have since become useful reagents in organic synthesis,^2a-cBecause the isocyanide group is readily hydrolyzed to the corresponding amine, metalated iso-cyanides provide a convenient means of nucleophilic introduction of α-aminoalkyl groups into organic molecules. For example, the reaction of metalated 2-isocyanopropionic ester with benzylbromide provides, following acid hydrolysis, α-methylphenylalanine.³Alternatively, reactions of α-Metalated isocyanides with various electrophilic reagents such as ketones, thioketones, Schiff bases, etc., permit an efficient route to the resulting heterocycles (oxazolines, thiazolines, imidazolines, etc.).