Alkyl and aryl isocyanides have a unique carbene-like structure with a formally divalent carbon atom. Their electronic structure can be represented by the resonance formula 1'and 1''. They are readily accessible by a variety of methods and are important substrates for several useful synthetic transformations including the Passerini and Ugi reactions.[1] Many of these reactions proceed by the attack of a carbon electrophile at the isocyano group,[2] ...
