Visible-light-promoted oxidative halogenation of alkynes

• Published in: Chemical communications (Cambridge, England) Vol. 55; no. 95; pp. 14299 - 1432
• Main Authors: Li, Yiming, Mou, Tao, Lu, Lingling, Jiang, Xuefeng
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 26.11.2019; Royal Society of Chemistry
• Subjects: air; Alkynes; ambient temperature; bioactive properties; Biological activity; Catalysts; Chemistry; Chemistry, Multidisciplinary; Crystallography; drugs; Electron transfer; Halogenation; light; Metabolites; oxygen; Physical Sciences; Room temperature; Science & Technology; secondary metabolites; ALCOHOLS; OXYGEN; KETONES; ALPHA,ALPHA-DIBROMOACETOPHENONES; BROMINATION; BONDS; ALPHA; OXYHALOGENATION; CATALYSTS; WATER
• ISSN: 1359-7345; 1364-548X; 1364-548X
• DOI: 10.1039/c9cc07655g

In nature, halogenation promotes the biological activity of secondary metabolites, especially geminal dihalogenation. Related natural molecules have been studied for decades. In recent years, their diversified vital activities have been explored for treating various diseases, which call for efficient and divergent synthetic strategies to facilitate drug discovery. Here we report a catalyst-free oxidative halogenation achieved under ambient conditions (halide ion, air, water, visible light, room temperature, and normal pressure). Constitutionally, electron transfer between the oxygen and halide ion is shuttled via simple conjugated molecules, in which phenylacetylene works as both reactant and catalyst. Synthetically, it provides a highly compatible late-stage transformation strategy to build up dihaloacetophenones (DHAPs). In nature, halogenation promotes the biological activity of secondary metabolites, especially geminal dihalogenation.