Visible-light-promoted oxidative halogenation of alkynes
作者:Yiming Li、Tao Mou、Lingling Lu、Xuefeng Jiang
DOI:10.1039/c9cc07655g
日期:——
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
N-chlorosuccinimde, selective oxyhalogenations of alkynes were achieved in water under very mild conditions. No halogenation at the aromatic rings was detected, and control experiments revealed the radical pathway. The easily conducted protocol exhibited high reproducibility, was readily adjusted to gramscale, and allowed for recycling of reaction medium and catalyst.
Halogenation: A simple, highlyefficient, and environmentally friendly facile method is presented for the synthesis of dichloroacetophenones and dichlorophenylacetophenones from aryl terminal and internalalkynes, respectively, by using CuCl2 as Cl-radical generator and air (oxygen) as an oxidant under low-energy visible light irradiation at room temperature.