Radical chemistry of nitrosoarenes: concepts, synthetic applications and directions.

Nitrosoarenes are readily available and highly reactive, making them promising building blocks in organic chemistry. The recent development of radical conversions of nitrosoarenes provides an alternative and powerful platform for the facile construction of a wide range of sterically hindered secondary amines and high-value N-heterocycles that are difficult to obtain through other means. Accordingly, a great variety of radical transformations such as additions, cascade reactions by radical relay, and multi-component reactions of nitrosoarenes have been extensively developed. In this review, we aim to summarize the recent progress on the radical reactions of nitrosoarenes with special emphasis on the scope, limitations, and underlying working mechanism. Hopefully, this review will provide a useful guideline for researchers for further exploration of valuable radical transformations and applications of nitrosoarenes.