1,3-Dipolar Cycloaddition of Nitrile Imine with Carbon Dioxide: Access to 1,3,4-Oxadiazole-2(3<i>H</i>)-ones
作者:Chun-Xiao Guo、Wen-Zhen Zhang、Ning Zhang、Xiao-Bing Lu
DOI:10.1021/acs.joc.7b00963
日期:2017.7.21
Efficient synthesis of 1,3,4-oxadiazole-2(3H)-one was achieved by CsF/18-crown-6 mediated 1,3-dipolar cycloaddition of nitrile imine and 2.0 MPa of CO2. CsF/18-crown-6 played a key role in enhancing the reactivity of CO2 as a 1,3-dipolarophile. The practical utility of this transition-metal-free approach to 1,3,4-oxadiazole-2(3H)-one is highlighted by the convenient synthesis of a commercial herbicide
通过CsF / 18-crown-6介导的腈亚胺的1,3-偶极环加成和2.0 MPa的CO2,可以实现1,3,4-恶二唑-2(3H)-1的高效合成。CsF / 18-crown-6在增强CO2作为1,3-偶极亲子的反应中起着关键作用。这种无过渡金属的方法对1,3,4-恶二唑-2(3H)-one的实际应用通过方便地合成市售除草剂Oxadiazon和MAO B抑制剂得到了强调。