title: I2-Mediated 2H-indazole synthesis via halogen-bond-assisted benzyl C-H functionalization.
abstract: I2-Mediated benzyl C-H functionalization has been developed for the synthesis of 2H-indazoles, which features high efficiency, simple conditions and no need for metals. Mechanistic experiments and DFT calculations have revealed halogen bond assistance and a radical chain process for this reaction. The azo group and the bound iodine cooperate in the hydrogen abstraction step, which circumvents the thermodynamic disfavor of direct hydrogen abstraction by a simple iodine radical.
authors.affiliation: Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China. cjxi@tsinghua.edu.cn.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Yi
authors.affiliation: Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing 100084, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Jiao
authors.affiliation: Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China. cjxi@tsinghua.edu.cn and State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Xi