Radical Addition of Hydrazones by α-Bromo Ketones To Prepare 1,3,5-Trisubstituted Pyrazoles via Visible Light Catalysis
作者:Xiu-Wei Fan、Tao Lei、Chao Zhou、Qing-Yuan Meng、Bin Chen、Chen-Ho Tung、Li-Zhu Wu
DOI:10.1021/acs.joc.6b00992
日期:2016.8.19
novel efficient tandem reaction of hydrazones and α-bromo ketones is reported for the preparation of 1,3,5-trisubstituted pyrazoles by visible light catalysis. In this system, the monosubstituted hydrazones show wonderful reaction activity with alkyl radicals, generated from α-bromo ketones. A radical addition followed by intramolecular cyclization affords the important pyrazole skeleton in good to
visible和α-溴代酮的新型高效串联反应据报道可通过可见光催化制备1,3,5-三取代的吡唑。在该系统中,单取代与由α-溴代酮生成的烷基自由基表现出出色的反应活性。自由基加成,随后进行分子内环化,以良好至优异的产率提供了重要的吡唑骨架。这种在温和条件下具有宽泛的群体耐受性的有效策略为1,3,5-三取代的吡唑提供了一种潜在的方法。