Kralj Magdalena, Lukin Stipe, Miletić Goran, Halasz Ivan
Ruđer Bošković Institute, Bijenička c.54, 10000 Zagreb, Croatia.
J Org Chem. 2021 Oct 15;86(20):14160-14168. doi: 10.1021/acs.joc.1c01817. Epub 2021 Sep 7.
Performing reactions in the solid state offers the largely unexplored possibility of influencing reactivity by manipulating the solid form of the starting reactants. In this work, we explore the use of various solid forms of barbituric acid and its effect on reaction paths and kinetics in a Knoevenagel condensation reaction with vanillin. Modifications of barbituric acid included the use of its desmotrope, a cocrystal, and a salt as the starting reactant. Comparing these reactions with the reaction starting from the commercial keto tautomer of barbituric acid, we find that the reaction kinetics could be accelerated or decelerated, together with a change in the reaction mechanism. Exploring solid forms of reactants can be used as general methodology for manipulating mechanochemical reactivity, further highlighting the benefits of conducting reactions in the solid state, because many of the modifications of solids become unavailable upon dissolution.
在固态下进行反应提供了一种很大程度上未被探索的可能性，即通过操纵起始反应物的固体形式来影响反应活性。在这项工作中，我们探索了使用巴比妥酸的各种固体形式及其在与香草醛的克诺文纳格尔缩合反应中对反应路径和动力学的影响。巴比妥酸的改性包括使用其互变异构体、共晶体和盐作为起始反应物。将这些反应与从巴比妥酸的商业酮互变异构体开始的反应进行比较，我们发现反应动力学可以加速或减速，同时反应机理也会发生变化。探索反应物的固体形式可以用作操纵机械化学反应活性的通用方法，进一步突出了在固态下进行反应的好处，因为许多固体的改性在溶解后就无法实现了。
