Transition metal-free construction of trinuclear N-fused hybrid scaffolds by double nucleophilic aromatic substitution under microwave irradiation

Treatment of 2-(2-bromoaryl)- and 2-(2-bromovinyl)benzimidazoles with 2-aminoazoles in the presence of a base under microwave irradiation triggers double C(sp²)-N coupling to form trinuclear N-fused hybrid scaffolds. A reaction pathway involving nucleophilic aromatic substitution (S_NAr) accompanied by ammonia evolution is proposed as a key step of this transition metal-free process.