Organic transformations of isocyanides classified by their activation strategies

Abstract

Isocyanides have been extensively utilized in organic synthesis to construct valuable chemical structures. Classical Ugi 4‐component reaction is the robust method to access diversely functionalized peptoids. By using well‐established cyclization techniques, a variety of nitrogen heterocycles from commercially accessible compounds have been efficiently synthesized. Several transition metal‐catalyzed processes have been developed to utilize isocyanide as a useful carbonyl nitrogen synthon. Recently developed synthetic methods, such as C–H bond activation and visible‐light photocatalysis, have been adopted to the isocyanide chemistry to enhance the efficiency, availability, and novelty of the chemical processes. This review summarizes the reactivity of isocyanide classified by the activation modes of electrophilic, nucleophilic, and radical species, together with the seminal discoveries and recent advances in the past 10 years.

Heterocycles via SiCl4-Promoted Isocyanide Additions to Oxonitriles

“…The unique bonding of the terminal carbon of isocyanides is exceptionally well-suited for synthesizing heterocycles . The versatility stems from the carbenoid nature of the isocyanide carbon that provides a 1,1-bis-connection point for bond-forming reactions with electrophiles, nucleophiles, transition metal complexes, and radicals . Employing isocyanides as 1,1-bis-connectors in cascades provides an extremely versatile strategy for rapidly preparing complex heterocycles …”