Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles

• DOI: 10.3762/bjoc.21.15
• Publication Date: 2025-01-30T09:45:11Z
• Authors: Yujun Pang; Jinglan Yan; Nawaf Al-Maharik; Qian Zhang; Zeguo Fang; Dong Li
• Keywords: Reaction conditions; Radical cyclization

An efficient and eco-friendly approach for synthesizing difluoromethyl- aryldifluoromethyl-substituted polycyclic imidazoles was established via a visible-light-promoted radical cyclization reaction. This method employed the readily accessible inexpensive CF 2 HCO H or PhCF COOH, along with benzimidazoles bearing unactivated alkenes PhI(OAc) as substrates, proceeded without need of any base, metal catalyst, photocatalyst additive. In total, 24 examples were examined, all them successfully underwent reaction to produce target products in good excellent yields. Mechanistic studies revealed that proceeds pathway.