S‐Nucleophilic Imidazoline Ring Expansion: a Novel Approach to the Formation of Medium‐Sized Thiolactames

Abstract

A novel method has been successfully developed for the synthesis of medium‐sized heterocycles containing thioamide groups. This approach facilitates the expansion of the imidazoline moiety within the condensed ring system through the action of S‐nucleophiles, enabling access to a broader and more diverse chemical space for natural product analogs and bioactive compounds. A series of [1,4,7]thia‐(oxa−)diazecin‐9‐thiones were efficiently synthesized from diarene‐fused [1.4]heteroazepines using this transformation, achieving yields ranging from 28–58 %.