Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide
Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide
复制标题
DOI：
10.1038/nature22316
复制
发表时间：
2017-05-04
期刊：
影响因子：
64.8
通讯作者：
Martin, Ruben
中科院分区：
文献类型：
--
作者：
Julia-Hernandez, Francisco;Moragas, Toni;Martin, Ruben
催化碳-碳键的形成使得组装复杂分子时的合成路线能够简化（1）。这是特别重要的饱和烃，这是常见的图案在石化和生物相关的分子。然而，涉及烷基亲电体的交叉偶联方法仅在特定的和先前官能化的位点处导致催化键的形成（2）。在这里，我们描述了一种催化方法，该方法能够在大气压力下用二氧化碳促进在远程和未官能化的脂肪族位点的羧化反应。该反应通过催化剂沿着烃侧链（3）的选择性迁移而发生，具有优异的区域选择性和化学选择性，与经典的交叉偶联反应相比，表现出显著的反应性中继。我们的研究结果表明，位点选择性可以切换和控制，使官能化的反应性较低的位置在先验的反应性更高的存在下。此外，我们表明，从石油加工，如烷烃和未精制的烯烃混合物，散装获得的原材料，可以用作基板。这提供了一个机会，通过直接转化石油衍生的原料，在生产有价值的脂肪酸的过程中整合催化平台（4）。
Catalytic carbon-carbon bond formation has enabled the streamlining of synthetic routes when assembling complex molecules(1). It is particularly important when incorporating saturated hydrocarbons, which are common motifs in petrochemicals and biologically relevant molecules. However, cross-coupling methods that involve alkyl electrophiles result in catalytic bond formation only at specific and previously functionalized sites(2). Here we describe a catalytic method that is capable of promoting carboxylation reactions at remote and unfunctionalized aliphatic sites with carbon dioxide at atmospheric pressure. The reaction occurs via selective migration of the catalyst along the hydrocarbon side-chain(3) with excellent regio- and chemoselectivity, representing a remarkable reactivity relay when compared with classical cross-coupling reactions. Our results demonstrate that site-selectivity can be switched and controlled, enabling the functionalization of less-reactive positions in the presence of a priori more reactive ones. Furthermore, we show that raw materials obtained in bulk from petroleum processing, such as alkanes and unrefined mixtures of olefins, can be used as substrates. This offers an opportunity to integrate a catalytic platform en route to valuable fatty acids by transforming petroleum-derived feedstocks directly(4).