Quinine synthesis studies: a radical-ionic annulation via Mn-mediated addition to chiral N-acylhydrazones.
Quinine synthesis studies: a radical-ionic annulation via Mn-mediated addition to chiral N-acylhydrazones.
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奎宁合成研究：通过锰介导的手性 N-酰腙加成的自由基离子环化。
DOI：
10.1021/ol7017938
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发表时间：
2007
期刊：
影响因子：
5.2
通讯作者：
Friestad,GregoryK
中科院分区：
文献类型：
--
作者：
Korapala,ChandraSekhar;Qin,Jun;Friestad,GregoryK
仅使用1.25当量的烷基碘就实现了官能化全氢异喹啉的自由基离子环化方法，该方法涉及锰介导的烷基碘和手性N-酰基腙的偶联。将该反应应用于奎宁路线上的含烯烃底物提供了适度的产率，随着规模的扩大而降低。对照实验表明，烯烃干扰偶联反应。一个修改后的方法，涉及前氧化的烯烃提供了93%的产率在锰介导的耦合，与作为一个单一的非对映体获得的加合物。
A radical−ionic annulation approach to functionalized perhydroisoquinolines involving Mn-mediated coupling of alkyl iodides and chiralN-acylhydrazones was achieved using only 1.25 equiv of the alkyl iodide. Application of this reaction to alkene-containing substrates en route to quinine offered modest yields, decreasing on scaleup. Control experiments revealed that the alkene interfered with the coupling reaction. A revised approach involving prior oxidation of the alkene offered 93% yield in the Mn-mediated coupling, with the adduct obtained as a single diastereomer.