Insights into Mechanochemical Reactions at Targetable and Stable, Sub-ambient Temperatures
Insights into Mechanochemical Reactions at Targetable and Stable, Sub-ambient Temperatures
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DOI：
10.1002/anie.201805263
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发表时间：
2018-10-01
影响因子：
16.6
通讯作者：
Mack, James
中科院分区：
文献类型：
--
作者：
Andersen, Joel;Mack, James
我们提供了对稳定和可验证的低温条件对机械化学反应的影响的见解。这些都是通过对SPEX 8000(M)混合器/磨机进行修改而实现的，可以对低温机械化学反应进行可靠的精细控制。以4-叔丁基环己酮的还原为模型体系，发现产物的非对映体分布与所选温度有很强的依赖性。在室温下，相同的甲醇还原反应表现出类似的立体选择性趋势。在这两种情况下，降低温度有利于提高选择性，尽管在无溶剂的机械化学条件下效果更为明显。这些结果表明，冷却罐提供了一个散热器，以减轻反应的放热特性。立体选择性也表现出对操作频率的依赖，尽管这种依赖的性质尚不清楚。我们的反应器的应用远远超出了这里所介绍的。
We provide insights into the effects of stable and verifiable, low-temperature conditions on mechanochemical reactions. These are made possible by modifications made to a SPEX 8000(M) Mixer/mill allowing reliable fine control of low-temperature mechanochemical reactions. Using the reduction of 4-tert-butylcyclohexanone as a model system we find the diastereomeric product distribution bore a strong dependence on the selected temperature. The same reduction in methanol at room temperature shows similar stereoselectivity trends. In both cases decreasing temperature favors increases in selectivity, although the effect is more pronounced in the solvent-free mechanochemical conditions. These results indicate that the cooled jar provides a heatsink to mitigate the exothermic character of the reaction. Stereoselectivity also showed a dependence on operating frequency, although the nature of this dependence remains unclear. Applications of our reactor extend far beyond what is presented herein.