Novel Chlorination of Imidazo‐Fused Heterocycles via Dichloro(aryl)‐λ3‐iodanes

• Published in: European journal of organic chemistry Vol. 2022; no. 30
• Main Authors: Dai, Peng‐Fei, Xu, Huiqin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 12.08.2022
• Subjects: Chlorination; Chlorine; Dichloro(aryl)-λ3-iodanes; Electrophilic substitution; Heterocycle; Mild conditions; Oxidizing agents; Reagents; Substitution reactions; Substrates
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.202200779

A novel, safe, convenient and efficient protocol has been developed for regioselective chlorination of imidazo‐fused heterocycles with dichloro(4‐(trifluoromethyl)phenyl)‐λ3‐iodanes under mild conditions. The present approach avoids the need of toxic chlorinating reagents, strong stoichiometric oxidants, metal catalysts or harsh reaction conditions. 36 examples of imidazo‐fused heterocycle substrates were investigated, and the chlorinated products were obtained with moderate to excellent yields. Control experiments indicated that the chlorinated reaction proceeded through an electrophilic aromatic substitution. An efficient protocol for chlorination of imidazo‐fused heterocycles with dichloro(4‐(trifluoromethyl)phenyl)‐λ3‐iodanes has been developed under very mild conditions. The present approach avoids the need of toxic chlorinating reagents, strong stoichiometric oxidants, metal catalysts and harsh reaction conditions. Control experiments indicate that the chlorinated reaction proceeds through an electrophilic aromatic substitution.