2-Isocyanoanilines and their mono-Boc-protected derivatives

Among the variety of synthetically useful isocyanides, 2-isocyanoanilines have been scarcely reported in the chemical literature, despite the rich chemistry that expectedly could derive from the reactivities of their two functional groups. This is the case not only for the parent compound but also for most of their N-monosubstituted derivatives. The reason behind such behavior relies upon their chemical instability, apparently attributable to the presence of the N-H bond. Among these latter species, two tert-butyl carbamates are notorious exceptions, as they have been widely utilized in multicomponent reactions but poorly described. This review covers the chemistry of these compounds from a critical perspective, analyzing the causes of the instability of these privileged molecular scaffolds, as well as highlighting the reactivity of their mono-Boc-protected derivatives.