Cationic [1,2]-Aryl shift in the design of poly(hetero)aromatic systems: from structure to functional materials

Abstract

Molecular rearrangements occupy an important place in organic chemistry because they make it possible to significantly modify organic molecules in a single step to obtain new compounds with desirable applied properties. Synthetic protocols based on molecular rearrangements are often favored over traditional method, as they can eliminate multi-step syntheses and the need for preliminary substrate functionalization, making these processes more resource-efficient and environmentally friendly. This review analyzes the development of [1,2]-aryl shift chemistry in the 21st century, including rearrangements in aromatic carbo- and heterocycles and their application in the synthesis of polyaromatic functional materials. Particular attention is paid to tandem (cascade) reactions involving, along with the cationic [1,2]-aryl shift, also the Scholl cyclization or oxidative coupling of aromatic systems. In addition to deepening the fundamental understanding of acid-mediated transformations, this review paves the way for the programmable design and synthesis of polyaromatic carbo- and heterocycles, opening exciting prospects in organic synthesis and materials design. This is the first review to address various types of tandem/cascade reactions involving the cationic [1,2]-aryl shift in various aromatic/heteroaromatic systems. The review, for the first time, traces the evolution of this rearrangement from a side process in transformations such as the Friedel-Crafts reaction or Scholl cyclization into a valuable tool in organic synthesis for the tuning the physicochemical properties of aromatic carbo- and heterocyclic compounds.