Iron-catalyzed intermolecular [2+2] cycloadditions of unactivated alkenes
Iron-catalyzed intermolecular [2+2] cycloadditions of unactivated alkenes
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DOI：
10.1126/science.aac7440
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发表时间：
2015-08-28
期刊：
影响因子：
56.9
通讯作者：
Chirik, Paul J.
中科院分区：
文献类型：
--
作者：
Hoyt, Jordan M.;Schmidt, Valerie A.;Chirik, Paul J.
环加成，例如形成六元环的[4+2]狄尔斯-阿尔德反应，是合成化学中最强大和最广泛使用的方法之一。类似的[2+2]烯烃环加成合成环丁烷在动力学上可以通过光化学方法实现，但底物范围和官能团耐受性有限。在这里，我们报道了铁催化的未活化烯烃的分子间[2+2]环加成以及烯烃和二烯的交叉环加成作为环丁烷的区域和立体选择性路线。通过合理的配体设计，这种贱金属催化方法的开发扩大了丰富的碳氢化合物原料的化学空间。
Cycloadditions, such as the [4+2] Diels-Alder reaction to form six-membered rings, are among the most powerful and widely used methods in synthetic chemistry. The analogous [2+2] alkene cycloaddition to synthesize cyclobutanes is kinetically accessible by photochemical methods, but the substrate scope and functional group tolerance are limited. Here, we report iron-catalyzed intermolecular [2+2] cycloaddition of unactivated alkenes and cross cycloaddition of alkenes and dienes as regio- and stereoselective routes to cyclobutanes. Through rational ligand design, development of this base metal-catalyzed method expands the chemical space accessible from abundant hydrocarbon feedstocks.