2-(Alkynyl)anilines and Derivatives — Versatile Reagents for Heterocyclic Synthesis

The transformations of 2-alkynylanilines and their derivatives into heterocycles are surveyed. Depending on the substituents, catalysts, and reaction conditions, these substrates can be converted into indoles, quinolines, indolines, oxindoles, indoxiles, various polycyclic compounds, etc. This review aims to generalize and assess the patterns of reactivity, selectivity, and applicability of 2-(alkynyl)anilines in heterocyclic chemistry. The review is divided into sections in accordance with the produced heterocycle. In summary, the title substrates are capable of cyclizing not only into five- and six-membered rings, but also to produce seven- and even eight-membered ring systems. The preparation of 2-(alkynyl)anilines is not covered. (Figure presented.). © 2022 Wiley-VCH GmbH